Tuesday, 1 May 2012

Version 3 focus group feedback

Small changes were made to the informed consent forms and prep sheet prior to the implementation. This included the integration of a question on the implementation of the current feedback system. The final version 4 prototype will be developed from these findings and final testing completed. There is potential for further work i.e. randomization functionalities which will be included in the project report.


Focus Group with Teddy Share Prototype v.3 Analysis & Evaluation

Summary:  The most important feedback gained from this was the need for an on/off switch as well as the potential for the audio message to change i.e. be randomised, or be customisable after the product is delivered. New audio data proposed: jokes or stories. User feedback pointed out the pros of not implemented a separate presence detection/indication system i.e. one that notifies a user that the remote user is there all the time so it will not be integrated into the prototype at this stage. Also, users should be instructed to only have the bears on when they are at home so that messages are not sent when they are not there. Even if they were not in the same room, a user could still hear the bear as its quite loud and it could draw them into the room where the bear was. Users were happy with the security and the context of use.

Initial questioning

The users responded positively to the prototype and it was important that problems raised in the previous focus group did not reappear. The users like the prototype and the ‘hugging’ gesture in interaction with the Monkey. The big teddies were both liked and disliked; one user found them a little to large for their room whilst others liked the form. Users liked the system and the fact that ‘you don’t have to make an excuse u to say hi’. One user mentioned amusement at the possible scenario where a person presses the button when the remote person wasn’t even there.

Context of use: All users said that they would use it. One user said she’d use it with her boyfriend, and put their special song on it. One said that they’d use it with friends to tell jokes. All users understood how to use it when presented with the manual, which was analysed separately. They all agreed with the presented usage of it within the home. All users were excited by the idea that the prototype could hold multiple audio tracks that could be randomised.

The users all liked the audio tracks and one member likened the process to ‘being like having someone request a song for you on the radio. You’d know that they’re thinking about you at the time. It is a bit more special than sending a test-you can get across more stuff’.
User base: the users developed a list of people that they could imagine using this system with. This included friends, partners and family. It was generally agreed that the users would have to know each-other quite well as otherwise ‘it could be kind of awkward’. One user disagreed with this saying that it could be given as a gift by someone you just started dating, and that it could be quite sweet. The general consensus was against this usage however and most said that they’d find it intrusive, especially if a voice recording was used instead of a song or something less personalised.

Interaction questions
All users found the closing arms control easy to manipulate which was extremely important. The interaction method was described as being unusual.

Users did not like the idea of a constant indicator to identify when the remote user was there. One user pointed out that it might interfere with the meaning of the ‘thinking of you message’. ‘I’d be like… ‘I know you’re at home… why aren’t you thinking about me’. Another user embraced the fact that it might be missed, and that the risk element was important to them. It would defeat the purpose in a way if you KNEW that your message was being received and that this makes it that bit more special. The whole point is to communicate with them at the time so if they miss it, they miss it, its all part of the package. There is the risk with normal communication i.e. texts that they may not get the message immediately anyway. The system is as much about sending the message as receiving it. Another user points out that it is good to know once the message has been sent that they received it. It might be good to know before so that you don’t just send the message for no good reason.

My response: the system incorporates a message validation system. If the remote users bear is off, the green feedback light does not flash. This happens within 4 seconds. Would you want a separate ‘enquiry’ button, as the system currently does both jobs? The user was happy with this response, although liked the idea of an enquiry button. Other users preferred the system the way it was, and one even said that they liked the idea of not being 100% sure if they were definitely there or not. They said that if both users simply turned their bears on when they were at home, even if they weren’t in the same room they would hear the music anyway. They said that the manual should include this instruction. This would prevent ‘wasted’ messages.
If an enquiry button was to be implemented, however, all users agreed that it would have to be very discrete. If there was indication of whenever the person was near the bear perhaps it could vibrate. There are numbers problems with this, but it was not further explored as users did not embrace either idea in general.

Security
The security was satisfactory for all users. One user stated that ‘You only have people in your home, and especially your bedroom, that you trust’, and the others agreed. They mentioned that if you wanted to give the product to a child to take to school, it might be useful to have extra security like a matching wristband to unlock everything.

Context of use
Other contexts proposed by the users were systems where the user could carry the object round with them which wouldn’t be so conspicuous. However this was disregarded due to the embarrassment factor.
All users would use it within the proposed context, but would record different data i.e .Jokes and Funny Stories. All of the users liked the idea of being able to record multiple messages which were either randomised or flipped through chronologically.

Thesis
The thesis was then analysed to see how well the prototype addressed it. The thesis has been tested in an extremely limited way, but serves as a starting point for further investigation. All users felt that the system conveyed presence and that they got a feeling of being connected to another person at the current point in time. ‘You know that they’re at home thinking about you which is really nice’. All users said that they felt that they knew exactly where the user was i.e. at home and what they were doing i.e. thinking about them. They said that they would not get the same feelings if they could press the button and play the audio at any point in time as you’d have no idea when they recorded It or where they are now or what they’re doing’.. ‘You’d get a reminder of the person which is quite nice, but I can’t imagine a situation where this would be useful. I could easily play the stuff on my computer with much better quality’. All users agreed that the output was valued more because it cannot be replayed at their discretion. One user summed it up; ‘You always want what you can’t have’.

Improvement questions
-An on/off switch would be useful
-The potential to change the audio whenever you want easily. This would make it more customisable and people would eventually get tired of hearing the same things.

Improvements to the v4  prototype:
·         The manual should say that the bear should be left on only when a user is home
·         An on/off switch should be integrated to prevent the batteries from burning out
·         The breadboard should be replaced with strip board to stop the wiring falling out




User Manual v 2.0 and 2.1

This is the new manual design developed for the focus group:

Inside

 Outside

Below is the edited version 2. A few changes have been made, such as the way that the bears are referred to, the addition of age and general guidelines as well as the way that information is presented visually. This leaflet is much better than the original. Less cutesy, more information is conveyed and in a much clearer way which is very important.


The inside.
Now that the manual and the prototypes are complete I'm ready for the focus group tomorrow. I have not done a pilot test as i did before as i feel that i am well prepared for it having done one recently and that I will not come across any new problems. What I hope to gain from this focus group is a final prototype design and a final manual design. I can then rapidly develop the website, and produce the advert and formalise my project. I may do another user evaluation method and a heuristic analysis to further triangulate my findings.

Note: There are some typos in the manual which will be rectified.

Prototype 3.1 Focus Group Prep & Informed Consent Forms

I have collected the responses to the screening questionnaire. Around 25 people were contacted via email, and 9 responded to the screening questionnaire link. Out of these 9, 8 were within the correct age range and were suitable in the fact that they understood the context; contacting someone who is far away. I have invited all 8 to a focus group scheduled tomorrow at 2 and hopefully at least 3 will turn up.

In preparation for this i am preparing a list of goals again using the DECIDE framework. This will allow me to develop a prep sheet similar to before to guide discussion I will also need these users to sign informed consent forms, which wont have to be changed much from before.


D - 'What are the high level goals of the evaluation...'
1.  Do they understand how it works.
2. Where does this fit into their lives.
3. Do they see any problems or improvements that could be made to make it better for you?
4. Do they like it?
5. Is the manual clear and easy to use?

E - 'Explore the questions'

1. Do you like and understand the prototype
2. Do you like the closing arms interaction?
3. How effective is the manual? Do you like the design of it? Is it easy to use?
4. Who are you? What do you use instead to let someone know you're missing them? Is the proposed system useful in sending this message?
5. Would you like to be able to know explicitly when the other users bear is on/off so you're not just guessing??
6. Do you like the name 'Share bear' and the strap-line 'Keep in touch... Literally'

C - Choose the evaluation approach and methods
1. Focus group. Qualitative and in a controlled situation. The use of portable functioning props means that they can move around the space and test out how they would work. Semi-structured, there will be no group brainstorming or drawing as this is analytical not creative. It will be presented as the 'share bear'. 

I - 'Identify the practical Issues... For example how to select users, stay on budget, stay on schedule, find evaluators, select equipment'
Users have been contacted and screened based on age and whether they have a person living away from them. This will help them relate to the context of use.  The focus group will be cost-free (barring snacks), and i will be the evaluator. Notes will be taken rather than audio, and a prep sheet will be created for easier note taking. Any interaction will be described for the purposes of evaluation.

D -'Decide about ethical issues... Develop an informed consent form. Users have the right to: know the goals of the study, know what will happen to the findings, privacy of personal information, leave when they wish, be treated politely'


E-Evaluate, Interpret and Present the data
Evaluation will done textually and visually.




Prep sheet



A.      Introduction: Introduce prototype and explain participation and ask them to read and sign consent forms. Re-iterate that participation is voluntary and that they may stop at any time
a.       ‘You are participating in an evaluation of the ‘Share Bear’ concept. It involves two teddy bears, each to be kept with a different person i.e. between siblings, parent and child, friends or boyfriend/girlfriend. The system is for people who are special and important to each-other, but are separated by distance. It allows users to play a pre-recorded message remotely by controlling a trigger on their teddy bear. This is transmitted wirelessly. You will be introduced to a prototype of this system which is in its finishing stages and nearly complete. You will be asked to interact with the bear, and assess it in a few different ways.
b.      DEMONSTRATE TEDDY BEAR-ask for a volunteer and give them the bear with the speaker in it!
c.       ‘By closing the bear’s hands you send a wireless message to the other bear and a notification ‘beep’ plays. When the other bear receives a signal it plays a pre-recorded clip (This clip would have been installed in the bear at purchase), and also communicates that the message has been received. The first bear lights up to let you know that the message was successfully delivered. If there is a fault with either bear, one or both of the notification signals won’t work.
d.      QUESTION Does everyone understand the basic function of the prototype?
e.      IF NO, re-explain it
f.        IF YES, continue to say that ‘I am asking you for your opinions of how the teddy bear works, if you’d use it and advancements and improvements that you would make to it. I will also ask you about security of the teddy bear’


QUESTIONS
Topic: Opinions, Context of user and user base
1.       What do you think of the prototype in general?
2.       Do you think it is useful?
3.       Would you use it?
4.       Do you understand how to use it?
5.       When would you use it?
6.       Is there anything you do not understand? How could it have been explained better.
7.       Who would you use this with?

Interaction questions
8. What do you think of the closed arms control? Is it easy/difficult? Do you like it?
9. Would you like to be notified of when the remote users bear is on? At the moment you will only know that the other bear is on when you try t interact and no feedback light shows up. Would you prefer a purpose built signal of some kind of show when it’s on or off? Or do you like it how it is? What kind of signal would this be and how would it work?


SECURITY
Explanation: Most users will want to be sure that it is their loved one sending them the message. At the moment the bear is protected by physical security i.e. being kept in a safe place and by being inconspicuous (other users probably wouldn’t know how to use this’
1. Is this security enough for you or would you prefer something else? In this case, What

CONTEXT
Explanation: This bear is been presented to you to be given to someone who is going away, or sent to someone that is away. It is at the moment for adults. However, it could be given to a child if you are the one who is travelling. 
1. Would you use it for any other context?
2. How would you use it? What information could you record on it?


I have made some small changes to the informed consent forms, namely the duration at 90 minutes. The content otherwise is still the same, and any ambiguities will be cleared up in the verbal introduction.

I do want to add in some questions that relate to my thesis. Namely, do you feel that it conveys presence, and do you feel that you cannot later 'pick up' the message and replay or re-experience is that it is more valuable. This will in a limited way test my thesis to see if it was successful. I will ask them to simulate being able to press a button to play the audio at their request.


THESIS QUESTIONS

Read Aloud: My thesis for this project is ‘Transient memory increases the value of memories transmitted between two people. It conveys a sense of presence and a feeling of being 'connected' to another person’. I want to ask you a few questions around it.

  1. By interaction with this prototype, do you get an idea of the other user being ‘present’ at a remote location
  2. Do you get the idea that they are CURRENTLY thinking about you
  3. Do you feel connected to that other person
  4. Would you get the same feeling of presence if you could push a button and play the audio at any time?
  5. Would you get the same feeling of connection to that remote person if you could push a button and play the audio at any time? If yes, would it be more, less, or about the same?
  6. Do you feel that you value the output more because you cannot replay it whenever you want? Because it is not accessible whenever you desire is it more valuable to you?

Version 3.1 Prototype development part 2

1. Make it possible for the receiving user to provide feedback of some kind


The feedback could essentially be a little 'thankyou'. However, i'm not sure what kind of output this should be, or if this is even necessary at all. The user may not even need a 'thankyou'. Perhaps the next step after they receive their message is that they may want to call that person if they have time. Perhaps the bears will be used at a time when the user may not be thinking to make a call, or even want to receive one. It fills a space where all the user needs to say it 'im thinking about you'. It is then upto the remote user to decide what they want to do with that message, if at all. If there is the option to interact, they may feel obliged to. 


There is however, now an answer to a question that comes up: how will the user know that the remote person is there? The bears wont always be on, so the remote user wont be able to transmit its feedback signal when it's off. If the user closes the bears arm, and the green feedback light doesn't blink, they know that the remote user isn't there OR that they turned the bear off. There will be an on/off switch that will be turned on whenever the user is at home. 


I have decided not to make it possible for the receiving user to provide feedback at this stage and instead to ask this in the next focus group. 


3. Put the voice clip & MP3 clip into one track: complete.


4. Incorporate the on/off switch. Parts have been reserved at Maplins and will be collected tomorrow for integration.


Note: Should the user be able to check whether the remote bear is on? Should there be a specific button for this? It may feel less like they're 'taking a chance'. I will ask the focus group members about this. 







Version 3.1 prototype development

These were the changes i needed to make to the prototype itself following the cognitive walk through.

1. Make it possible for the receiving user to provide feedback of some kind
2. Make the feedback for the sending message more gratifying i.e. a beep. Something which makes the teddy feel more 'interactive'.
3. Put the voice clip & MP3 in one clip (if both are used) as the MP3 naturally resets itself by playing the beginning of the most recent track, not the first song in the list.
4. Incorporate on/off switch so that the batteries aren't too badly drained (this can be done a little later).


The first thing i did was tweak the code so that the indicator light notified when the remote xBee had actually received the message, not when the button on the local xBee was pressed. This provides feedback that the communication is actually received, like a delivery report. 


This was done by adding a line of code to the relay xBee which said 'Send a notification when you receive a certain letter', and a line of code to the push button xbee which said 'turn the light on and off once when you receive notification that your message has been successfully received'. This was because according to Schneiderman's 8 golden rules I should offer informative feedback. I needed to add in notification that the message had been successfully received otherwise to give users some peace of mind knowing that their message had successfully got there. It also allows users to identify if the system is not working. In conjunction with feedback for when the message is sent, this provides a good error notifying mechanism which is Schneiderman's 5th rule 'Offer Simple Error Handling'. I can add error handling to the manual to say 'what to do if your message is successfully sent but you receive no feedback of it actually arriving'. 


The code changes are below


Arduino 1 (push button xBee)



if (Serial.read() == 'K'){
   
     digitalWrite(localINDICATOR, HIGH);
     delay(1000);  
      digitalWrite(localINDICATOR, LOW);
    delay(1000);  
    }

Arduino 2 


 if (val == 'D'){
     Serial.print('K');
      
      digitalWrite(relay, LOW); //TURN ON
 // delay(232000); i reduced the delay for developmental purposes-to see if everything worked correctly.
 delay(10000);
    digitalWrite(relay, HIGH); //TURN OFF
    delay(1000);
  
    } 




The next thing i did was to introduce a buzzer feedback for the user when the hands were touched together.  This would indicate that the message was successfully sent.


I used these guidelines for basic implementation: http://www.arduino.cc/en/Tutorial/PlayMelody and http://www.oomlout.com/oom.php/products/ardx/circ-06 and http://arduino.cc/en/Tutorial/Tone. As usual i tested the element seperately then incorporated it into my project.

This was my test code (developed mainly from http://arduino.cc/en/Tutorial/Tone). I had to create a separate pitches library, done by adding a new tab and renaming it. This will have to be added to the main code. I also moved the code from setup() to loop() so that it played repeatedly. I then added the pin as a global variable. The notes, their duration and delays are contained within arrays which would be useful when working with longer pieces, and also neaten up the code.


 #include "pitches.h"

// notes in the melody:
int melody[] = {
  NOTE_C4, NOTE_G3,NOTE_G3, NOTE_A3, NOTE_G3,0, NOTE_B3, NOTE_C4};

// note durations: 4 = quarter note, 8 = eighth note, etc.:
int noteDurations[] = {
  4, 8, 8, 4,4,4,4,4 };
int piezoPin = 9;

void setup() {
  // iterate over the notes of the melody:

}

void loop() {
  for (int thisNote = 0; thisNote < 8; thisNote++) {

    // to calculate the note duration, take one second
    // divided by the note type.
    //e.g. quarter note = 1000 / 4, eighth note = 1000/8, etc.
    int noteDuration = 1000/noteDurations[thisNote];
    tone(piezoPin, melody[thisNote],noteDuration);

    // to distinguish the notes, set a minimum time between them.
    // the note's duration + 30% seems to work well:
    int pauseBetweenNotes = noteDuration * 1.30;
    delay(pauseBetweenNotes);
    // stop the tone playing:
    noTone(piezoPin);
  }
}

I want the sound to be a short bell sound. I searched http://www.freesound.org/ for inspiration. I decided on a fun, retro sounding clip.


After some experimentation i came up with a four tone, video game sounding clip which i will add and include.

There are clips of the code:
int melody[] = {  NOTE_C4, NOTE_G3,NOTE_G3, NOTE_A3};
int noteDurations[] = {2, 4, 8, 2};
I had to change the loop at the bottom for 4 tones (I made this mistake on my first try without noticing and it made a horrible sound);
  for (int thisNote = 0; thisNote < 4; thisNote++) {

I also broke up the code into its own function called 'myTone' for modular integration.


void loop() {
myTone;
}

void myTone() { ...rest of code here...}

I noticed that it would be much simpler in fact if the tone code wasn't in a 'for' loop so save me having to write code to break out of it. I am going to restructure it. 

I also decided against having a multi-tonal indicator. It should only play once. 

I am using the new code below..

 #include "pitches.h"
int speakerPin = 9;
void setup() {
}

void loop() {
myTone();
}

void myTone() {
    tone(speakerPin, NOTE_C4,1000); //pin, not, duration
       delay(1300);
      noTone(speakerPin);     // stop the tone playing:  
}

I am incorporating this new code into the main code. 

This is the new code if (digitalRead(BUTTON) == LOW) {
        myTone(); 
 //   digitalWrite(localINDICATOR, HIGH); 
    Serial.print('D

This is the current system event architecture.



Still do to are: Task 1, 3 & 4. These will be completed in the next post. 


Cognitive Walkthrough

Tasks

1. Read the manual
2. Operate the bear

Do this for both prototypes; sending and receiving bears.

Prep: Record message, change device timings to match. Need to work out if it is better to send a song? Or even do a message AND a song. Try this all three ways in the focus group. Embed speaker wiring in receiving bear. Ensure that they are communicating with no blocking. Possibly may have to manipulate the antenna.

Internal build of the receiving bear (with a speaker). Used a seam ripper to open up the lining to make space for the electronics. This will be later sewn up. I made a small hole in the front to expose the xBee antenna if needed.


I am adding two tracks to the bear: the 'hi. just thinking about you' message which is 2 seconds and 'Use Somebody' by Kings of Leon which is 3:50, so 3:52 in total. I chose this track because it is quite sentimental, and fits with the concept of transmitting the memory that you are missing someone. Although the actual data being activated is old, it would have some significance to both users and by activating it, new memories are created of engagement with the artifact. I will increase the delay to ((60*3)+52)*1000=232,000. This is 3:52 converted into milliseconds as per the documentation on arduino delay coding here: http://arduino.cc/en/Reference/delay The Arduino delay is in milliseconds.

Notes on preparatory examination:

The MP3 player lost battery power so didn't work. I need to ensure that it is fully charged when presented at the viva and when submitted.

Also, the 9V arduino battery supply will only last for 5 hours maximum http://engineerzero.wordpress.com/2011/01/15/arduino-on-battery-power/ i noticed that one of my Duracell batteries had to already be replaced just through development. What i can do is introduce a power switch into the adaptor like a rocker switch http://www.maplin.co.uk/slim-line-rocker-switch-98091 To do this i will have to cut one of the wires, trim them , extend them and solder on the switch. This will turn the whole bear on and off.


The Cognitive Walkthrough A: THE TRANSMITTING TEDDY

Note: Instead of taking a voice recording I have taken notes, as the voice recording would have to be transcribed anyway.

1. The Manual

Fairly easy to understand. Need to point out how long to hold the hands together, and the fact it is the metal contacts which are important. A diagram would be really useful, or a set of photos of someone using it. It is really tiny and a bit tacky. A single folded instruction manual would be more professional. Looks like there is too little information on it. The font is quite hard to read and far too 'cutesy' for my taste actually.

2. The interaction

Some other kind of more gratifying feedback could come in useful i.e. a beeping sound or 'success' midi sound. This could replace the light completely. Might make it seem more interactive and less 'passive'. Although there is a feedback light, the transmitting user


The Cognitive Walkthrough B: THE RECEIVING TEDDY

1. The Manual

There was no manual so i was surprised when I heard the voice. It was a little scary and I would've immediately either thrown it away thinking it was faulty or spying on me or called the person who gave it to me. I need a manual to tell me what i need to do on my side.

2. The interaction

The voice clip does make it more personal, but to me it is a little cheesy. You know who is sending it to you, so do you need to hear the voice?? The song clip was more powerful in my opinion than the voice clip; it can hold a lot of memories. It was given to me as a gift, but i'd like to be able to let the other person know that i got their message and appreciate it. This could be something small like squeezing the bears hand to light up an LED on the receiving bear. When a message was sent a second time, the track started from the song only, and not the first track.


Overview of changes

1. Make it possible for the receiving user to provide feedback of some kind
2. Create a manual for the receiving teddy
3. Make the feedback for the sending message more gratifying i.e. a beep. Something which makes the teddy feel more 'interactive'.
4. Put the voice clip & MP3 in one clip (if both are used) as the MP3 naturally resets itself by playing the beginning of the most recent track, not the first song in the list.
5. Make the manual less 'cutesy', more informative and contain diagrams and troubleshooting information.
6. Incorporate on/off switch so that the batteries aren't too badly drained (this can be done a little later).

Monday, 30 April 2012

Predictive evaluation, Cognitive Walkthroughs & Heuristics

Predictive evaluation was a tool introduced in Kate Devlins HCI lectures in 2011. I am planning on applying it to the project as a form of prototype evaluation prior to its introduction to a focus group. This should allow me to identify any glaring issues and tweak the prototype accordingly before going to do a pilot test.


I am referring to a few resources whilst preparing for it: the book 'User Interface Design And Evaluation by Deborah L. Stone, Debbie Stone' as well as the following online resources http://courses.csail.mit.edu/6.831/archive/2008/lectures/L18-predictive-evaluation/L18-predictive-evaluation.pdf http://www.sigchi.org/chi96/proceedings/shortpap/Hamilton/hf_txt.htm. The importance of it as a n early developmental evaluation methodology is emphasised in the book (Chapter 19, page 406) 'Alyson: Heuristic or predictive evaluation and trial-based (user based) evaluation, complement each other. If we'd only used predictive evaluation, we wouldn't have had the response from the real individuals who are going to be affected by the system; as a usability assessor, I could have sat there and said "Yes, it's not going to affect memory load, yes the design is consistent,.... yes the design is simple." But I'm not a user. I wouldn't have known what it was like to use it for real.'


There are positive and negative aspects to said evaluation. In the first link (a PDF from a User Interfact Design lecture at MIT. 


'Today’s lecture is about predictive evaluation – the holy grail of usability engineering.  If we had an accurate model for the way a human used a computer interface, we would be able to predict the usability of a design, without having to actually build it, test it against real people, and measure their behaviour.  User interface design would then become more like other fields of engineering.  Civil engineers can use models (of material stress and strain) to predict the load that can be carried by a bridge; they don’t have to build it and test it to destruction first.  As user interface designers, we’d like to do the same thing. '

It points out the necessity of having a model for how a user interacts with an interface. This link http://www.usabilityfirst.com/usability-methods/hci-design-approaches/ gives a list of approaches to HCI and explains the GOMS method: Goals, Operators, Methods and Selection Rules. It was developed in 1983 by Stuart Card, Thomas P Moran and Allen Newell.

'Goals are defined as what the user desires to accomplish on the website. Operators are the atomic-level actions that the user performs to reach a goal, such as motor actions, perceptions, and cognitive processes. Methods are procedures that include a series of operators and sub-goals that the user employs to accomplish a goal. Selection Rules refer to a user’s personal decision about which method will work best in a particular situation in order to reach a goal.


The GOMS model is based on human information processing theory, and certain measurements of human performance are used to calculate the time it takes to complete a goal. For example, the average time it takes a human to visually fixate on a web page, move eye fixation to another part of the web page, cognitively process information, and make a decision of what to do next can be measured in milliseconds. The times it takes for each of these operators can be added up to produce the total time for a particular method. Multiple methods can be compared based on the total time to complete a task in order to determine which is the most efficient method for accomplishing the task.'
Advantages of doing predictive evaluation is that it doesn't involve users, or in some cases, require a prototype. It allows for comparison between different ideas and can identify problems before implementation is complete. 'predictive evaluation not only identifies usability problems, but actually provides an explanation of them based on the theoretical model underlying the evaluation... User testing might show that design A is
25% slower than design B at a doing a particular task, but it won’t explain why.  Predictive evaluation breaks down the user’s behaviour into little pieces, so that you can actually point at the part of the task that was slower, and see why it was slower.' - http://courses.csail.mit.edu/6.831/archive/2008/lectures/L18-predictive-evaluation/L18-predictive-evaluation.pdf

KLM is also useful wih predictive evaluation (Keystroke-Level Monitoring as it evaluates the time required by users to execute tasks. 'The first predictive model was the keystroke level model (proposed by Card, Moran & Newell, “The Keystroke Level Model for User Performance Time with Interactive Systems”, CACM, v23 n7, July 1978).. This model seeks to predict efficiency (time taken by expert users doing routine tasks) by breaking down the user’s behavior into a sequence of the five primitive operators shown here.

'Human Information Processing Model
Human Information Processing (HIP) Theory describes the flow of information from the world, into the human mind, and back into the world. When a human pays attention to something, the information first gets encoded based on the sensory system that channeled the information (visual, auditory, haptic, etc.). Next, the information moves into Working Memory, formerly known as Short-Term memory. Working Memory can hold a limited amount of information for up to approximately 30 seconds. Repeating or rehearsing information may increase this duration. After Working Memory, the information may go into Long-Term Memory or simply be forgotten. Long-Term Memory is believed to be unlimited, relatively permanent memory storage. After information has been stored in long-term memory, humans can retrieve that information via recall or recognition. The accuracy of information recall is based on the environmental conditions and the way that information was initially encoded by the senses. If a human is in a similar sensory experience at the time of memory recall as he was during the encoding of a prior experience, his recall of that experience will be more accurate and complete.'
Predictive evaluation involves task analysis, and it was not only this that i wanted to analyse. I also wanted to analyse how easy the prototype was to use, how easily the instructions are to follow and to generally analyse the interface. It is for this reaso that i have decided to do a 'cognitive walkthrough instead' which is a step by step analysis of the processes undertaken to interact with a system. Also as it is such a simple interface the tasks executed will be done quite quickly and taking timings will not be massively beneficial. My 'cognitive walkthrough' seeks to evaluate the presentation and execution of the system as a whole, not just timings of individual tasks. I am going to tweak this 'predictive evaluation' into more of a predictive walk-through with a novice user. I am going to use Schneiderman's 8 Golden Rules to assess whether my interface is successful with its accompanying manual http://faculty.washington.edu/jtenenbg/courses/360/f04/sessions/schneidermanGoldenRules.html

I am going to do a step-by-step evaluation of:

1. Reading the manual
2. Manipulating the bear
3. Closing communication

If any problems arise i will say them aloud, and will do a 'cognitive walkthrough' to identify every step that is being made. I will record the audio of evaluation and analyse the results. I will need an end user, and then will swap roles with that person to evaluate their responses. There will be two 'predictive evaluations. I will probably need two manuals as the two bears will be different. I will need to consider the possibility of proximity sensing 'how do i know they are there and received my message?'.

I will use this evaluation to create a version 3.1 prototype (and manual) which i will then do a pilot user test with and then a focus group.

I am referring to these guidelines on cognitive walkthroughs: http://www.usabilityfirst.com/usability-methods/cognitive-walkthroughs/ http://ics.colorado.edu/techpubs/pdf/93-07.pdf. I will also take timings on how long it takes to execute  individual tasks.