The descriptive statistics for each dependent variable are computed for each treatment group of the independent variable "Zoom Period". The treatment groups are as follows:
Each of these treatment groups has 10 subjects, for a total sample size of 30 subjects. The dependent variables are
The retention points are computed from the answer to the first question on the post experiment survey. Section 2.2 describes the computation of retention points.
The descriptive statistics for each dependent variable are presented in both tabular and graphical form. The plots present the sample mean for each treatment group as a horizontal dark line, the range of values between -1 and 1 standard deviations of the sample mean as a shaded rectangle, and the range of data values as a vertical interval passing through the rectangle. The following sections of this document present these descriptive statistics.
The total time to complete the task is analyzed twice. The first set of values are simply the elapsed time from start to finish. The second set of values removes the effect of delays induced by the treatment of zoom period. This is done by subtracting the quantity
(# hyperlinks) * (zoom period)
from the total elapsed time.
| Treatment | Mean | Std. Dev | 95% Confidence Interval
for Mean Lower Bound |
95% Confidence Interval
for Mean Upper Bound |
| 1 (0.00 s) | 207.14 | 28.28 | 186.91 | 227.37 |
| 2 (0.25 s) | 248.92 | 96.04 | 180.21 | 317.62 |
| 3 (0.50 s) | 259.47 | 82.03 | 200.79 | 318.16 |
| Total | 238.51 | 75.62 | 210.25 | 266.77 |
| Treatment | Mean | Std. Dev | 95% Confidence Interval
for Mean Lower Bound |
95% Confidence Interval
for Mean Upper Bound |
| 1 (0.00 s) | 207.14 | 28.28 | 186.91 | 227.38 |
| 2 (0.25 s) | 236.32 | 94.74 | 168.55 | 304.09 |
| 3 (0.50 s) | 237.62 | 80.16 | 180.28 | 294.96 |
| Total | 227.03 | 72.34 | 200.02 | 254.04 |
| Treatment | Mean | Std. Dev | 95% Confidence Interval
for Mean Lower Bound |
95% Confidence Interval
for Mean Upper Bound |
| 1 (0.00 s) | 44.30 | 10.52 | 36.77 | 51.83 |
| 2 (0.25 s) | 50.40 | 14.00 | 40.38 | 60.41 |
| 3 (0.50 s) | 43.70 | 5.89 | 39.49 | 47.91 |
| Total | 46.13 | 10.74 | 42.12 | 50.15 |
| Treatment | Mean | Std. Dev | 95% Confidence Interval
for Mean Lower Bound |
95% Confidence Interval
for Mean Upper Bound |
| 1 (0.00 s) | 1.80 | .4216 | 1.49 | 2.10 |
| 2 (0.25 s) | 2.00 | .67 | 1.52 | 2.47 |
| 3 (0.50 s) | 1.90 | .99 | 1.19 | 2.61 |
| Total | 1.90 | .71 | 1.64 | 2.17 |
When scoring the retention points, we noticed that the most common pattern of answers to the retention question was to circle Bergen and Oslo only. This effect was particularly notable for the subjects under treatment 1. Here 8 out the 10 circled these two cities, and the other 2 circled only Oslo. The subjects in the two animated zoom groups did not have quite as high a proportion of "Bergen/Oslo" answers, but a substantial fraction of the other answers were also "off by one city" from just circling Bergen and Oslo (either one city added or one city omitted from those two). The table below summarizes this data.
| Treatment | Bergen /Oslo only | Any other set |
| 1 (0 sec) | 8 | 2 |
| 2 or 3 | 10 | 10 |
