Is a Picture Worth A Thousand Words : Results

Response Times to Questions

Although we expected the image-only group to perform better that the text-only group, clearly that was not evident in the results. In fact, both groups performed similarly. The control group, which used both text and images simultaniously, exhibited worse results than the experimental groups. This indicates a possible problem with our experiment.

time
(sec)		 a                
24                
22                
20                
18                
16                  
14             20  
12     18.3   17.8      
10                
                 
      image   text   both  
      visual method

Error Rates

An error is when the subject clicks on the wrong web page. Consider that we grouped the web pages into two groups; those that could be identified visually and those that could be identified textually. After reviewing the data we can only say that subjects in the text only group made more errors while identifying web pages with imagery. Likewise, subjects in the image only group made more errors while identiying web pages with text..

rate                      
1.4                    
1.3                    
1.2                    
1.1                    
1.0                    
0.9                    
0.8                    
0.7                    
0.6                    
0.5                    
0.4                    
0.3                    
0.2                    
0.1                    
                     
      image   text  
      treatments  

key
red - web pages with imagery
blue - web pages with text
green - both

Subjective Responses

83% of subjects stated in the post-experiment survey that they would use Padprints again, if they had access to it. All of the test subjects in the image-only group and a majority of the text-only group said they would use Padprints again.

There were a few sugestion for improvement of Padprints. For subjects in the text only group, they state that a longer title would be more useful. Subjects from the image-only and image and text groups prefered larger images. A majority of people from all three groups requested a better zooming mechanism.

Discussion

Our experiment ran into several problems. The computer used for testing was rather slow. PadPrints took a long time to reload itself and Netscape after a page was selected. The software crashed during one of the experiments. The LINUX environment had a virtual desktop which may have had an impact on the subjects' performance.

Only one of the subjects took advantage of the ZUI. He Zoomed in on each thumbnail in order to answer the questions, thereby, reducing his time significantly.

The computer science majors knew a priori that Dr. Kruskal had a beard. So they answered that question in very litle time


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