# A one-way between subjects ANOVA

I have 3 visualization techniques (e.g., PC, NL and Map). I wanted to evaluate user performance (Time and Accuracy) for these three visualizations methods. I have 9 tasks for participants to perform. These 9 tasks categorized into 3 groups such group 1 , group 2 and Group 3 (each groups contains 3 tasks). I ran between subjects with 36 participants (12 for each visualization method). I asked participants to perform same tasks in all three visualizations. Now I have 6 table which task completion time and Accuracy (whether participant could successfully perform the tasks or not) for 3 different visualization.

One:  Completion time for PC visualization method

Participant 1 ......... Participant 12

Second : Accuracy for  PC visualization method

Participant 1 ......... Participant 12



How should I analyse these 6 tables? should I apply Anova? if yes which Anova method is the best one for my case? How should I apply Anova for accuracy where the results for accuracy is binary?

you might need to clarify your experiment design but as I understand it: you have 3 groups of visualisation (PC, NL, Map) and 3 different types of task (group 1,2,3) - resulting in 9 combinations. Therefore you have 9 subgroups (e.g PC,group1, PC,group2...Map,group3).

You should do a 2x3 ANOVA - not a oneway ANOVA as you suggest in your title, if your outcome measures are continuous. If your outcome measure is binary, or otherwise categorical, consider a chi square test or logistic regression.

It sounds like the same people perform in all subgroups. You can therefore use repeated measures 2 x 3 ANOVA.

• Thanks for the response. Do I need to run between subject ANOVa test since I have 36 participants. 12 of them performing tasks for PC visualization, another 12 for Map and remaining 12 NL visualization. – Bahador Saket Mar 18 '14 at 21:27
• You have 3 types of visualisation, but also a number of different types of task (3 types of task???). To see if there is only a different between visualisation type ignoring what type of task the participants did) you'd run a 1 way ANOVA - with visualisation as your only factor (between subjects if you used the same subjects for each visualisation condition)..... – user41270 Mar 19 '14 at 17:01
• ...however, it might be better to determine if there is an interaction between task and visualisation. This might show that some visualisations work particularly well with some kinds of task. For example, in a one way ANOVA you might find Map is best. But in an ANOVA with visualisation and task as factors (e.g a 3x3 ANOVA - if you have 3 tasks) you might see that Map is the best technique with tasks 1 & 2, but worst for task 3. This would mean that results from the oneway ANOVA are misleading. Map is not best overall - only for task 1 and 2. It is, in fact, worst for task 3. – user41270 Mar 21 '14 at 10:11
• sorry read 2x3 not 3x3 – user41270 Mar 21 '14 at 14:34
• Thank you for the answer. By conducting 2x3 Anova, I would definitely be able to see some visualisations work particularly well with some kinds of task but what if I would also be interested to see which one works best in general for all tasks? Should I first apply 1 way between subject anova to see the general performance and then conduct 2*3 Anova ? or by conducting 2*3 anova at the first place I would be able to find all answers. – Bahador Saket Mar 23 '14 at 15:22

I applied 2*3 between ANOVA and wrote my results. Could you please have a look at it and see it makes sense or not.

Accuracy