DECEMBER 2020 48 HOUR ASSESSMENT SCHOOL OF COMPUTER SCIENCE MODULE CODE: CS5040 MODULE TITLE: Human Computer Interaction Principles and Methods TIME TO HAND IN: 48 hours EXAM INSTRUCTIONS a. Answer all 3 questions b. Each question indicates the number of marks it carries. The paper carries a total of 60 marks. This assessment consists of exam-style questions and you should answer as you would in an exam. As such, citations of sources are not expected, but your answers should be from your own memory and understanding and significant stretches of text should not be taken verbatim from sources. Any illustrations or diagrams you include should be original (hand or computer drawn). You may word-process your answers, or hand-write and scan them. In either case, please return your answers as a single PDF. If you handwrite, please make sure the pages are legible, the right way up and in the right order. Your submission should be your own unaided work. While you are encouraged to work with your peers to understand the content of the course while revising, once you have seen the questions you should avoid any further discussion until you have submitted your results. You must submit your completed assessment on MMS within 48 hours of it being sent to you. Assuming you have revised the module contents beforehand, answering the questions should take no more than three hours. 1. Experimental Design (a) A user study was designed to assess the usability of three bespoke input interfaces for a watch – pressure, twist and pan input. To characterize the performance of each condition, the three interfaces were modified and measures for two variables collected: input entry times and errors. The experiment was conducted in a quiet lab and took between 40 to 60 minutes to complete. Before the study participants were debriefed and demographics collected. The same participants took part in each condition and the three interface conditions were balanced in a Latin- squared design order. After completing the targeting task, participants rated the perceived usefulness and usability of each interface using a 7-point Likert scale. (i) What makes this a controlled experiment? Identify the key elements in this design which make it a controlled experiment (e.g. experimental design, variables involved etc.) [5 marks] (ii) What type of statistical test might one use to compare the means of the input entry times and why? [2 marks] (iii) What type of statistical test might one use to compare the perceived usefulness ranking and why? [2 marks] (iv) Discuss the ecological validity of this experimental design for the interfaces [3 marks] (v) With respect to the experimental design outlined in this question, describe four prominent threats to experimental validity. [4 marks] (b) For each of the following experiments below, describe (i) a suitable experimental design (within subjects, between subjects or mixed subjects design) (ii) the independent variable(s), (iii) one dependent variable and (iv) any skills transfer problems. (i) The experimenter wants to test which of two spatio-temporal routing visualization techniques (e.g. A 2D versus a 3D visualisation) is more successful in terms of user speed and accuracy when navigating to a destination. The same underlying map data is used in both visualization techniques. [2 marks] (ii) The experimenter wants to test whether users type faster on a keyboard if they type phrases drawn from particular sets of phrases and for particular presentation styles. [2 marks] [Total marks 20] 2. Interaction Design and Evaluation (a) TK SmartRun Inc. have hired you to develop a new wearable music player for their new target customers, elite marathon runners. Create 2 personas for this. [4 marks] (b) MokuTV inc. scenario “You are hired by a company called ‘MokuTV inc.’ to help them understand their target audience. They are developing a product called SmartTVdata and in this study they wish to determine if study participants can detect different coloured objects on a 4K display if the objects are large and occur on screen for a longer period of time (rather than only being visible for a short duration). They aim to vary the object colour, object size and object visibility duration and measure the detection rate of each participant. MokuTV inc aims to show that with SmartTVdata they can more efficiently transcode a video stream and not impact on the user experience of the TV while vastly reducing bandwidth costs” With respect to the MokuTV inc scenario, describe: (i) How you would go about recruiting participants to participate in a study while the product is still under early development. [2 marks] (ii) The precise details of a screener you would develop and how you might use it in a recruitment process. [2 marks] (c) Compare and contrast mobile phone text entry with wrist-worn smart watch text entry (consider issues such as usability, speed and accuracy). [2 marks] (d) A company has developed a prototype smartwatch that allows the user to use the surrounding skin on their wrist as an extension of the watch screen for visualisations and interaction. (i) Describe four issues (for novice and first time use) a HCI professional should consider when incorporating the novel interaction technique into their smart watch. [4 marks] (ii) Researchers decide to evaluate the prototype for the success of user interaction. Describe the advantages, disadvantages and appropriateness of a laboratory study versus a field study to evaluate this form of input. [4 marks] (iii) Suggest two metrics you would consider for the evaluation of the interaction technique and explain how would you use them in the study. [2 marks] [Total marks 20] 3. Qualitative and Quantitative Analysis: (a) Critically appraise this interview about Microsoft Teams, labelled “MS Teams Interview”. Ensure you comment on each of the following (i) question strength or weakness and (ii) interview structure/approach. [4 marks] Numbered lines with Interviewer speaking labelled (I), interview subject reply (S). [Interview starts at 14.22.00] 1. I: So, everyone uses Teams now, how many people call you on Teams each day/week? 2. S: About 10 people but I use it to send text messages to friends every few hours 3. I: Don’t you think we should just have Teams on phones instead of traditional calls? 4. S: Errrr, I guess so, yes 5. I: Ok, when you started using Teams what made it most interesting for you? 6. S: Gosh, errr, it’s been a while. I think I had to use it when I was working in Australia a few years ago but it’s hard to say. 7. I: Rate from 1 to 4 the most important features of Teams to you, where 1 is least important and 4 is most important. 8. S: Video Calls (1), Audio Calls (3), Text Messages (4), Sending File/Images (2) 9 I: Which of these new features is most important to you? Online gaming integration, AR Emoji or setting up a smart avatar, which can reply to incoming, calls for you? 10: S: If I had to pick, I guess the avatar but I’m not quite sure how that might work 11: I: Does Teams do anything that’s particularly useful to you in a way that it might not have been designed for? If so, what is it? What makes it useful? 12: S: Oh yeah, my wife thinks this is crazy but I use it for keeping our weekly shopping list. 13: I: Thank you for your time and we will report back to you our overall results [Interview ends at 14.26.14] MS Teams Interview (b) Name an approach that a researcher could use to analyse the qualitative data gathered from interviewing people about their use of MS Teams, and an advantage that using this approach would bring. [2 marks] (c) A museum is developing an Augmented Reality device for visitors to interact with exhibits and enhance their experience of the museum space. The device will be given to visitors at the main entrance desk and returned at the end of their visit. The curators of the museum intend to use the device to help them plan improvements to the physical space of the museum. A researcher has been asked to evaluate the prototype device. The researcher plans to carry out a questionna
ire survey of museum staff and visitors to gather quantitative data about them and their use and opinions of the system. Describe how the researcher might analyse the quantitative data collected from the questionnaire surveys collected from staff and visitors to the museum. [5 marks] (d) With respect to Fitts’ law: we test two new computer mice (mouse A and mouse B) with 128 participants. Each participant uses each mouse in a reciprocal Fitts’ law task. (i) For device A, given an SSerror of 1,000 and an SStotal of 20,000, what is the coefficient of determination (R2) and how do you interpret the result? [1 mark] (ii) For device B, given an SSerror of 20,000 and an SStotal of 100,000, what is the coefficient of determination (R2) and how do you interpret the result? [1 mark] (iii) Which R2 is higher and what does this allow us to say about device A versus B? [1 mark] (e) In a between-subjects experiment we collect the following errors for Keyboard A and Keyboard B. A B SSA SSB SSA+B 4 10 4 4 26 7 13 1 1 20 9 16 9 16 49 7 10 1 4 5 3 11 9 1 40 Mean 6 12 Sum 24 26 140 Mean A+B 9 The Keyboard A group has 3 participants and Keyboard B has 3. There are 10 participants in total. Given the above table of values, answer the following questions with respect to a one-way analysis of variance (ANOVA) for a between-subjects design with two levels of a single independent variable). (i) With an ANOVA there are two independent estimates of the population variance that can be obtained. What are these estimates and how are they related? [1 mark] (ii) The SStotal is 140 so what are the values for SSerror and SSeffect? [1 mark] (iii) There are 10 participants in total spread over 2 groups so what are the values for dferror, dfeffect, MSerror and MSeffect? [2 marks] (iv) With an α Confidence Level of 0.05 and hence a critical value of 5.32, what is the F-ratio value, and what is the test significance at this level? And what does this mean? [2 marks] [Total marks 20] *** END OF PAPER *** 欢迎咨询51作业君
