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This course delves into the essential role of experimentation in Human-Computer Interaction (HCI). We investigate how to ascertain whether product A outperforms product B and analyze design principles through rigorous testing. With a focus on understanding user behavior and the complexities involved in human-centered design, we explore context, participant selection, and the statistical tools needed to derive meaningful insights from experimental data. Join us in navigating the intricate landscape of HCI experiments and enhancing user experience through empirical research.
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Experiments in HCI • We do experiments in Human-Computer Interaction because we want to know ... • Is product A better than product B? • What is good and bad about X? • Testing design principles and methods • Etc. etc.
Experiments in HCI • Experimentation in HCI is all about people • As they will use the products we develop • But we also – less often - do experiments without human involvement • e.g. testing software capabilities • Strictly speaking this is not HCI, but usually a people-oriented aim
Experiments in HCI • Raw materials for experiments: • People • On their own horribly complex and varied things to test • ... And we usually run tests with groups of people! • Computer interfaces • And software, experiences, designs, art, etc. etc.
Experiments in HCI • People as objects of study: • People are different • Skills, knowledge, expertise • Tiredness, illness, motivation • They think and learn • => highvariability in experimental results • => hard to obtain significantresults
Experiments in HCI • People are also subject to complex effects, that are hard to control for (measure the effect of) in experiments • Time of day effects • Tiredness, post-lunch dip, etc. • Transfer effects • Learning and interference
Experiments in HCI • Other problem is that of context: Experiments can be done in the field or the laboratory • Each their own strengths and weaknesses • Since we usually involve groups of people, we have problems with accounting for the effect of social dynamics • ... and group relationships – how do they impact on what we want to measure?
Experiments in HCI • Finding subjects for experiments is (also) challenging • Nearly always, we have specific criteria that we would like participants to fulfill • Females, age 30+, driving a powder-blue prius, who likes liqourice • Often we do not have the money to pay people, so hard to get the right ones • This leads to the problem of most Psychology and HCI experimental research being done with Psychology and Computer Science undergraduate students • But how representative are they of the target population we are interested in?
”Statistics is the least of your problems!” Alan Dix, ”Avoiding Damned Lies”
Statistics • Statistics is a tool for analyzing data from experiments and deriving meaning from them • Statistics is a logical process – each type of problem has one or more statistical methods that can be employed • If you can identify the problem, you can find the statistical test to use • Finding help/guides for statistical tests is pretty easy
Statistics • Statistics is primarily used when we are looking for ”broad and shallow” results • Using surveys, data logging, large experiments • When using quantitative methods (i.e. Getting numbers as data) • If we want meaning – in-debt knowledge about just a few subjects, we use qualitative methods (numbers as data) • Video logs, not post-task walkthroughs, anecdotal evidence, etc.
Statistics • If we want to conclude... ”95% of users had problem X” - we use statistics ”Problem X happens for this reason ...” - we use qualitative methods Ideally both! Backup the quantitative data with qualitative – give meaning to the numbers! When I grow up, I want to be a HMW
Statistics • Statistics are an incredibly powerful tool for an HCI person (interaction design, usability, whatever ...) • In this course, focus on applying statistical methods to analyze experimental data • Somequalitativemethodsalso, but mostly this is in the course Target Group Analysis
The rest of the lecture • Practical information about the course • Course objectives • Course textbooks • Course plan • Exercise: • Table-top hockey experiment
About your course convener • Center for Computer Games Research • Mostly teaches at DDK-line • Empirical researcher: Science by experimentation • Mostly focused on experiments with humans (annoying bastards!) • User experience analysis in interactive applications • Games, websites, etc.
Practical information • Lectures Wednesday 10-12 in room: 4A22 • Exercises Wednesdays 13-15 in room: 4A58 • Exercises starts at 13.00 – ends at 15.00 (you can stay longer if you wish!) • Handouts for exercises on the course website (generally the week before): http://experimentdesign.wordpress.com
Things to know ... • Read the course handbook carefully – it contains important information (it is available on the website) • On the website you will find handouts, exercise guides and other documents used in the course, as well as updates and messages from the course convener: http://experimentdesign.wordpress.com
Aims of the course: • Basic grounding in research skills and research methodology • Designing and running experiments • Data analysis using statistics, SPSS and Excel • Writing up studies using standard presentation conventions • Designing questionnaires and fielding surveys • Ethics in research • Laws of interaction design
Course textbook: Will also be used: Sage, 2006 Field and Hole (2003). Sage publications. Field (2005). Sage publications
Don´t loose your textbook • You will be using it throughout the course
Other good statistics textbooks: Pearson / Prentice Hall 2005 Pearson / Prentice Hall 2004
Exam and assessment • The course will be assessed 100% via the final exam • Exam is written, with aids, on a PC, but minus internet access. • Exam will focus on testing your understanding of the principles taught in the course • It will focus on problem solving and thinking, not remembering the curriculum word by word • Note that changes may happen … • During the course there will be an assortment of assignments, some to be handed in, some to present, during the semester • These do not count towards your grade • Without doing them you will learn nothing …
Getting assistance • This is a method course, which can be intimidating • If you need help, get help – problems are easier to fix early on • Primary help: Ask you co-students and the people in your group • Secondary: Contact the course convener during office hours • Office hours: Thursday 10.30-12.00, Monday 10-30-12. Room 4B06. • DO NOT disturb outside office hours
Reading • Each week there will be some core reading • From Field & Hole • Or from the compendium • Some weeks there is also optional reading suggested – strongly encouraged that you read this • (I will be watching you ...)
Plagiarism and collusion • Plagiarism: Passing of someone else´s work or ideas as your own. • Don´t do it – risk being expelled or taking the course again • Collusion: Working with someone else and claiming that the jointly-produced work is entirely your own • Important point: When NOT working in groups, your work must be unique to you
Tabletop hockey experiment • Aims: • To show you how experiments work in practice • The de-mystify the process
Outline • Testing how far an improvised hockey puck travels under different conditions • Two factors (or conditions) are involved: • Shot type • Puck placement along stick • Each factor has two levels (or values): • Shot type: Wrist shot, slap shot • Puck placement: Near end of stick, middle of stick
Outline • So we have 2 factors with 2 levels: This is called a ”two level factorial design” – a very traditional experiment design in engineering sciences • The aim is to test all possible combinations of factors and levels – here 4:
Outline • In order to make sure our results are valid, we need to run each combination multiple times • Do 10 shots with each combination. Record distance travelled for each shot • Make sure you set up each shot exactly according to the guidelines – otherwise you introduce experimental error
Outline • Follow the experimental procedure in the handout • The handout is on the course website: www.experimentdesign.wordpress.com • Follow the guidelines for how to analyze the experimental data + answer the questions given • When everyone are done we will discuss the results jointly in class