tag:blogger.com,1999:blog-15731428165280298572024-03-05T05:32:19.755-08:00Ling Luo2012 Honours Thesis -- Cognitive Load Measurement through Pen GestureLing Luohttp://www.blogger.com/profile/05474097422388397162noreply@blogger.comBlogger36125tag:blogger.com,1999:blog-1573142816528029857.post-66475470533877192042012-10-25T19:45:00.000-07:002012-10-28T19:45:34.204-07:00Final Treatise<div style="text-align: justify;">
After two rounds of revision, I finally handed in the treatise, which is the biggest assessment for this project, on Wednesday.</div>
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The main body consists of 6 chapters -- the Introduction, Literature Review, Design, Analysis, Discussion and Conclusion. It also uses some graphs and tables to help illustrate the problem. The treatise shows what I have done and what I have learnt through the whole project from March to October.</div>
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Now, I will start to prepare the presentation on November 12th or 13th.</div>
<br />Ling Luohttp://www.blogger.com/profile/05474097422388397162noreply@blogger.com1tag:blogger.com,1999:blog-1573142816528029857.post-16953453718423507252012-10-12T21:00:00.000-07:002012-10-16T23:59:19.653-07:00Draft Treatise<div style="text-align: justify;">
This week, I have been working on the draft version of the treatise, and submitted the soft copy online this afternoon.</div>
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Although I got several separated documents which I edited during the process, it still took me a great efforts to write the treatise. Despite of the compulsory description of experiment design, implementation and analysis, I would like to focus on the learning process and trade-off decisions I made during the whole project. Thanks to all the documentations, notes and online blogs, it was not too hard to recall all details in each phase.</div>
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Up to now, the draft treatise includes the introduction, literature review, experiment design, implementation work and part of the analysis. Next week, I will continue to work on the draft and want to finish the main body before Thursday evening.</div>
Ling Luohttp://www.blogger.com/profile/05474097422388397162noreply@blogger.com0tag:blogger.com,1999:blog-1573142816528029857.post-89218560505680755062012-10-05T04:24:00.004-07:002012-10-05T04:24:31.478-07:00Data Analysis 2.2<div style="text-align: justify;">
This week I finished the further analysis of symmetry of m by adjusting the height of the line, to move it up and down a bit. I also test the feature on external dataset as well. The result is similar to what I got from the middle line.</div>
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Then I organised the results and start to edit the draft treatise. I discussed with the supervisor about the outline, and got a clear idea of what to write in each part.</div>
Ling Luohttp://www.blogger.com/profile/05474097422388397162noreply@blogger.com0tag:blogger.com,1999:blog-1573142816528029857.post-21903433384588029162012-09-28T16:00:00.000-07:002012-10-04T18:17:16.414-07:00Data analysis 2.1<div style="text-align: start;">
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This week, I finished the first letter specific feature's analysis -- symmetry for letter m.</div>
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I took these steps to extract the feature</div>
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Step 1: scan the file, and if the gesture is m, find the bounding box and compute the middle line function y = b</div>
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Step 2: pass the b value (from step 1) and the corresponding list of points to find all crossing points, and store them in another list - cross point list. If two adjacent points Point 1 and Point 2 are on different sides of the line y = b, I consider the second point as a crossing point.</div>
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Step 3: filter some of the gestures according to the number of crossing points.</div>
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Only 1 crossing point: maybe a gesture that was not logged properly</div>
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Too many crossing points (e.g. 12 crossing points in Gesture 31 from Subject 10): the subject wrote two m…</div>
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Step 4: compute length of segments, and check which is on the left and which is on the right.</div>
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Step 5: get the ratio between two segments. Here, I use right_segment_length / left_segment_length, and compute average value for each level</div>
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The result shows that there are only significant differences in limited conditions. I think this is a potential feature, but still need adjustment to investigate in more details.</div>
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Ling Luohttp://www.blogger.com/profile/05474097422388397162noreply@blogger.com0tag:blogger.com,1999:blog-1573142816528029857.post-41531728873871415442012-09-21T18:27:00.000-07:002012-09-24T18:28:02.459-07:00Data Analysis 1.3<div style="text-align: justify;">
I finished statistical tests for basic features like dimensions of bounding box, pen pressure and length of the gesture. I mainly use statistical methods including t-test and ANOVA. The results are not as good as expected, but I still found something. For example, the gesture length in the session 1. However, how to combine my result with external dataset and gave a generalised explanation is not easy to do.</div>
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In the next phase, I will focus on the letter-specific geometrical features for letter a, g and m.</div>
Ling Luohttp://www.blogger.com/profile/05474097422388397162noreply@blogger.com0tag:blogger.com,1999:blog-1573142816528029857.post-3491200871268731452012-09-14T00:39:00.000-07:002012-09-14T00:39:10.042-07:00Data Analysis 1.2<div style="text-align: justify;">
Today, I added the what subjects wrote during the experiment to the logging files. As it was almost impossible to collect what they wrote on-fly without recognition package, I took letters down by observing them writing. However, the problem is that I have to add the letter tag manually in the logging to facilitate further analysis.</div>
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It took me longer time than I expected, and I also encountered several formatting problems. Finally, all the gesture has the corresponding letter tag at the end of the gesture. It helps me to understand the importance of constructing logging files. If the format is not right, it may bring a lot of problems in the future stages.</div>
Ling Luohttp://www.blogger.com/profile/05474097422388397162noreply@blogger.com0tag:blogger.com,1999:blog-1573142816528029857.post-71646526640806920322012-09-07T00:28:00.002-07:002012-09-07T00:28:36.881-07:00Data Analysis 1<div style="text-align: justify;">
I have finished the user experiment on Tuesday, and started the first phase of data analysis.</div>
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First of all, I computed the accuracy of all questions to get an overview of the task performance. Then, I did the Friedman ANOVA on the subjective feedback to validate my experiment design (i.e. difficulty for each level). </div>
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In the next step, I'll continue to analyse the features I've tested on the external dataset, and focus on the letter specific features.</div>
Ling Luohttp://www.blogger.com/profile/05474097422388397162noreply@blogger.com0tag:blogger.com,1999:blog-1573142816528029857.post-92012571840489615062012-08-30T17:50:00.001-07:002012-08-30T17:50:16.834-07:00Conduct the Experiment<div style="text-align: justify;">
This week, I conduct my user experiment in the lab. Up to now, I have finished 7 out of 12, and all experiments are expected to be finished before next Tuesday. Since I've got some experience from the summer project, this time everything goes smoothly.</div>
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Next week, I will start the analysis of my dataset, and compare some of the result from the external dataset. I think it would be good to get some inspiration from my dataset and in turn do further analysis to the external dataset.</div>
Ling Luohttp://www.blogger.com/profile/05474097422388397162noreply@blogger.com0tag:blogger.com,1999:blog-1573142816528029857.post-62781047518309519692012-08-24T00:18:00.001-07:002012-08-24T00:18:13.975-07:00Experiment Implementation 5<div style="text-align: justify;">
This week I improved my implementation according to the result in the pilot study and finalised the experiment on Wednesday. I also finished booking subjects, and the experiment will start on next Monday. It will take about 1 hour and 10 minutes per subject, including 10 minutes instruction explanation and training time.</div>
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As the logging format is similar to the external dataset, so I think after the experiment, I could modify previous data analysis scripts to get some basic feature results. However, I still need explore more "letter specific" features before the end of the analysis.</div>
Ling Luohttp://www.blogger.com/profile/05474097422388397162noreply@blogger.com0tag:blogger.com,1999:blog-1573142816528029857.post-42069151419602296312012-08-17T00:19:00.000-07:002012-08-17T00:19:01.596-07:00Experiment Implementation 4<div style="text-align: justify;">
Today, I do a formal pilot study to tune the parameter of the experiment, such as time arrangement, task difficulty and settings of the tablet.</div>
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First of all, I increased the task difficulty a bit, which I think could make the task harder to complete than before. Then, I also adjust some time arrangement, like resting time between two sections and between two figures as well. Finally, the angle of the tablet is tested by three separate pilot runs. Taking two factors into consideration -- the average pen pressure and the proportion of points which reached the pressure limit, I adjust the angle to be 30 degrees from the vertical plane.</div>
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Additionally, I also finish the consent form and the subjective ratings.</div>
Ling Luohttp://www.blogger.com/profile/05474097422388397162noreply@blogger.com0tag:blogger.com,1999:blog-1573142816528029857.post-60314304868147948942012-08-15T21:58:00.005-07:002012-08-15T21:58:52.352-07:00Experiment Implementation 3<div style="text-align: justify;">
I think the experiment implementation has been finished, except for the pictures will be used in the experiment. I've drawn draft ones, but the size and layout of them needed to be fixed. Additionally, I edited subjective questions and summary table to be filled in during the experiment.</div>
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Tomorrow, I will do further pilot on task difficulty and time arrangement, and hopefully I can start booking subjects. According to the timeline, the experiment will take place on next Wednesday. </div>
Ling Luohttp://www.blogger.com/profile/05474097422388397162noreply@blogger.com0tag:blogger.com,1999:blog-1573142816528029857.post-23041880944574441762012-08-10T00:18:00.003-07:002012-08-10T00:18:55.585-07:00Experiment Implementation 2<div style="text-align: justify;">
During the implementation, the most challenging part for me is the user interface. In my project, I use Java Swing to realise the interaction between the user and the machine, and special logging package to collect the experiment data.</div>
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Currently, the main problem for me is how to display the gesture feedback on the screen in real time. I have to get familiar with GlassPane as soon as possible, and then apply it in front of other panels to show the trace to the subject.</div>
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Next week, the time arrangement for each part will be tested in the pilot study and the experiment implementation is hopefully to be finalised before the end of next week.</div>Ling Luohttp://www.blogger.com/profile/05474097422388397162noreply@blogger.com0tag:blogger.com,1999:blog-1573142816528029857.post-19862392210914325122012-08-05T18:13:00.003-07:002012-08-05T18:13:52.177-07:00Experiment Implementation 1<div style="text-align: justify;">
There are several parts in the implementation, including program for main tasks, pictures used in the task and the subjective rating. As I have finished the experiment description, it will be relatively easy to follow those steps to finish the implementation.</div>
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Currently, I have some issues in choosing the platform, so I need to test the compatibility of two different WACOM tablets first.</div>Ling Luohttp://www.blogger.com/profile/05474097422388397162noreply@blogger.com0tag:blogger.com,1999:blog-1573142816528029857.post-60249551648361247742012-07-30T22:44:00.001-07:002012-07-30T22:44:35.412-07:00Experiment Desgin<div style="text-align: justify;">
I finished the design and documentation of my experiment v1.0. Before the end of this week, I will finish the pictures used in the experiment and the main implementation.</div>Ling Luohttp://www.blogger.com/profile/05474097422388397162noreply@blogger.com0tag:blogger.com,1999:blog-1573142816528029857.post-18673627542240887252012-07-28T22:42:00.000-07:002012-07-30T22:45:00.827-07:00Data Analysis 1.3<div style="text-align: justify;">
I did further data analysis about the average gesture pressure and gesture length. For these two features, I also used the normalisation to to eliminate the effect on the value from the target letter, e.g. the shape or the way to write that letter.</div>
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1. Pressure: The mean value indicates that the pressure tended to be larger in the high load session than the normal session, but the p-value is greater than 0.05, which means the differences between two sessions are not significant.</div>
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2. Gesture Length: in Lisa's paper, she noticed the significant effect of cognitive load on gesture length. In my analysis, I added the normalisation step, and the p-value is still less than 0.05. It means there is a significant differences between average gesture length in the high load session and normal session.</div>
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In the next stage, I'll do more analysis related to the gesture length, and try to come up with more features.</div>Ling Luohttp://www.blogger.com/profile/05474097422388397162noreply@blogger.com0tag:blogger.com,1999:blog-1573142816528029857.post-32655639193478328632012-06-14T23:16:00.000-07:002012-06-14T23:16:08.169-07:00Data Analysis - 1.2<div style="text-align: justify;">
I finished the width/height ratio normalisation, and then I did the t-test to compare the new normal and stress results. There are no significant differences between them, with p-value (two-tail) > 0.05. Although this feature fails to be a good feature, I learnt a lot from the normalisation process. What is more, I think this idea can be used in the future analysis as well, because the differences between letters may also have other impacts on the gestures.</div>Ling Luohttp://www.blogger.com/profile/05474097422388397162noreply@blogger.com0tag:blogger.com,1999:blog-1573142816528029857.post-27376116454101043592012-06-12T00:15:00.003-07:002012-06-12T00:16:02.699-07:00Data Analysis-1.1<div style="text-align: justify;">
After discussing with my supervisor, he suggest me to normalise the width/height ratio for different letters, so that it can eliminate the effect of the generic shape of the letter. Then, I will explore more about the bounding box, to understand it in more details and compare my results with the experimenter's results.</div>
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In the further analysis, I need to use the actual written letter to group gestures, instead of the automatic recognition, so I need another field in the Stroke called "written". Since I have already summarised all the recognition errors, I will use the list to correct recognition result for each gesture. </div>Ling Luohttp://www.blogger.com/profile/05474097422388397162noreply@blogger.com0tag:blogger.com,1999:blog-1573142816528029857.post-72643218818830666902012-06-08T00:59:00.002-07:002012-06-08T00:59:56.242-07:00Data Analysis - 1<div style="text-align: justify;">
I would like to start the analysis from an easy and straightforward feature -- bounding box. First of all, this week I wrote some scripts to abstract bounding box information from processed data (one file for each subject), like the width, height, and width over height ratios. Then, I computed average values for different sessions (Normal and High). I will use t-test to compare two groups of results.</div>
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However, there are some issues I want to discuss with the supervisor. The most important one is the letter's shape has significant effect on the bounding box, and I am not sure whether I can compare the result. Additionally, I am not sure how to deal with slant, which the stoke is not vertical to the plane, because slant stroke will change the dimension of bounding box.</div>Ling Luohttp://www.blogger.com/profile/05474097422388397162noreply@blogger.com0tag:blogger.com,1999:blog-1573142816528029857.post-78685315260340127892012-05-31T18:14:00.000-07:002012-06-04T18:20:50.316-07:00Progress Report - 2<div style="text-align: justify;">
I have finished the progress report, and it helped me to summarise what I have done in this semester, especially the papers I have read. </div>
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At the end of the report, I attached a new Gantt Chart, adjusting the time allocation of the rest tasks. There are really a lot of things to do in the next stage, as my data analysis and experiment implementation are a bit behind the schedule. As to the literature review, I still need more articles about the pen-input features.</div>Ling Luohttp://www.blogger.com/profile/05474097422388397162noreply@blogger.com0tag:blogger.com,1999:blog-1573142816528029857.post-55536002066018397392012-05-18T17:24:00.000-07:002012-05-21T17:25:17.213-07:00Progress Report<div style="text-align: justify;">
Today, I started editing the progress report. It will cover the project introduction, literature review, current progress, future work and revised project plan.</div>
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For the most important part -- literature review, I would like to summarise the notes I took in the previous two months, and introduce the fundamental theory under my project, including working memory model, cognitive load theory, measurement and research on the pen gesture. The current progress will cover the data analysis of the external dataset, and my experiment design version 1.0.</div>
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My aim is to finish this report before the end of next week, and discuss with the supervisor for any issues in it.</div>Ling Luohttp://www.blogger.com/profile/05474097422388397162noreply@blogger.com0tag:blogger.com,1999:blog-1573142816528029857.post-8265660706990737612012-05-16T18:04:00.000-07:002012-05-17T18:20:36.033-07:00Some ideas about the experiment design<div style="text-align: justify;">
Today, I discussed experiment design with my supervisor. Currently, I designed three different tasks, which are graph transforming task, counting task and math operation task.The tasks involve recalling, applying rules and processing information. They use number of rules, time limit and amount of information to manipulate the cognitive load levels.</div>
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As my hypothesis for this experiment is related to the cognitive recovery time, so an important point in the experiment is how to control the task order and rest time between them. Now, I haven't come up with the detailed plan, but I would do more research on this topic and conduct some pilot study on it in June or July.</div>
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The supervisor also reminded me that I need to think about how to make the task adaptive to different people according to their real-time performance. </div>Ling Luohttp://www.blogger.com/profile/05474097422388397162noreply@blogger.com0tag:blogger.com,1999:blog-1573142816528029857.post-73883246203047189722012-05-14T22:17:00.003-07:002012-05-14T22:17:56.596-07:00Features for data analysis<div style="text-align: justify;">
About plotting, I added labels, including the gesture number, cognitive load level and recognise result, on each gesture to show the attribute clearer.
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Also, I reviewed two papers discussing the gesture features. They are all about the geometrical features of a gesture, ranging from simple ones like length, bounding box, and some complicated ones curvature and sharpness. In the papers, these features were used in handwritten recognition or input mode detection. They gave me some ideas about the feature selection, and I will search for more papers in the topic "online input recognition" (--> general features) and "handwriting verification" (--> subjective features). For my study, the features should be sensitive to the cognitive load and easy to test. I think the sharpness and other features related to angles between certain points might be potential good features, and I will summarise and test them in the next stage.</div>
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<br />Ling Luohttp://www.blogger.com/profile/05474097422388397162noreply@blogger.com0tag:blogger.com,1999:blog-1573142816528029857.post-7567190552615603922012-05-04T15:58:00.000-07:002012-05-08T21:04:32.607-07:00Preview of the Dataset - 2<div style="text-align: justify;">
Today, I finished the plot of the gesture, from which I got a clearer overview of the dataset. The python scripts were used to plot all the gestures according to the gesture position (x, y) and cognitive levels. The original size of the letter (about 4000 * 4000) is too big to display on the screen, so I zoomed them out to fit all the gestures from one subject into one screen (2056 * 1024). The reason why I arranged them in one screen is to make it easier to find potential features by comparing all the gestures at the same time. Currently, the gestures are ordered by time.</div>
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The next step for me is to look into those gestures and try to find interesting and valuable features to test. And another thing to be finished before the end of the next week is to summarise the frequently used features for further reference. </div>Ling Luohttp://www.blogger.com/profile/05474097422388397162noreply@blogger.com0tag:blogger.com,1999:blog-1573142816528029857.post-38476824844677382922012-04-27T16:32:00.000-07:002012-04-30T18:01:06.845-07:00Preview of the Dataset<div style="text-align: justify;">
Today, I did some preprocessing of the gesture data.</div>
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With the help from the supervisor, I removed all the blank line in the log, and I also checked the integrity of the data from three files by the userId and timestamp.</div>
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Currently, I have some questions to think about. Firstly, the priority of the research, which feature should I start from? Then, every gesture has about 50 points collected, how to consider those points as a whole, and looking for the trends of them.</div>
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I need to write data parsing scripts these days and before the end of the May, the analysis of some basic features should be finished.</div>Ling Luohttp://www.blogger.com/profile/05474097422388397162noreply@blogger.com0tag:blogger.com,1999:blog-1573142816528029857.post-11941365681387070122012-04-24T17:52:00.000-07:002012-04-30T17:53:42.158-07:00Literature Review<div style="text-align: justify;">
Today, I continued the literature review. The focus is on the experiment design.</div>
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The paper Reducing Cognitive Load by Mixing Auditory and Visual Presentation Modes (Mousavi, Low & Sweller, 1995) introduced 6 experiments, which tested the hypotheses in levels.Experiments are designed according to the results from the
previous experiments, to test some new hypotheses, so that at last, they could
explain the whole thing more thoroughly and clearly. Although, for the honours project, the time may not allow me to do more than one experiment, it is a good idea to apply in the further study.</div>
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Another paper, Free-form Pen-Input as Evidence of Cognitive Load and Expertise (Ruiz, Taib & Chen, 2011), explored the use of the scratchpad and the cognitive load. I think the reason for why pen input needs to be researched is quite important for me. It provides background information for my project.</div>Ling Luohttp://www.blogger.com/profile/05474097422388397162noreply@blogger.com0Sydney, Australia-33.873651 151.2068896-33.8868345 151.1871486 -33.860467500000006 151.22663060000002