- maybe she made a mistake in the parameters she gave us ?
- the slope of the regression lines are not at all the same
- for my trial (blue), I am faster at the begining but I also take more time at the end
- Cecile takes more time but seems more consistant in her results
From that experiment, I must say that it was really hard for me to do the experiment.
- I have a terrible vision, then clicking on a 1px line was hell.
- My screen may have been to bright, so it was very exhausting for my eyes
Because of that, I choose to do an other "witness study" that will be used as a base of comparing parameters... but with different parameters that will be less exhausting to test.
### Test 2 : Witness study
The parameters I choose have to be greater than Cecile's (to be less exhausting to experiment), but it also need to give a wild range of IDs. I choose to have a range from 2 to 5, with the following parameters :
Surprisingly, the two experiment give almost the exact same results !
I then had a look on the data and I noticed that the "test 3" gained one level of difficulty, comparing to "test 2".
Data from test 2 :
| MT (mean) | ID |
| ------ | ------ |
| 385 | 2 |
| 595.5 | 3 |
| 723.75 | 4 |
| 891 | 5 |
Data from test 3 :
| MT (mean) | ID |
| ------ | ------ |
| 561.5 | 3 |
| 704.75 | 4 |
| 911 | 5 |
| 1054.5 | 6 |
As I compared only similar IDs (I intentionally dropped ID 2 from "test 2" and ID 6 from "test 3" to really be able to compare the curves), then I have the same results.
My conclusion to this experiment is that doubling the distance is totally adding a level of difficulty in the task, and that I should be more careful on the data I work on.
The conclusion of this test is that doubling the distance definitely make the experiment harder, here I gain 1 ID.
Then, I wanted to test the Fitt's Law on a different device. I am used to use the mouse, but what about the tactile pad ?
Hypothesis : Using the tactile pad will increase a lot the difficulty, I will take more time to do the same task as "test 2".
### Test 4 : mouse vs tactile pad
I will keep the exact same parameters from the witness experiment, to see if the device have an impact on my results.
- Width : 5,10,15 px
- Distance : 50,100,150,200 px
- Number of trials : 6
Here are the results (blue dots : with tactile pad ; red dots : witness test, with mouse) :