数据可视化代写｜Information Visualization Coursework 3
This experiment aim is to test our ability as a group in evaluating data to conclude which method being a pie chart or a bar chart is the better choice in visualizing data. In this case, the percentage of students who get different degree classifications will be our question for our graph trials aimed to our participants.
For this experiment we have decided to use the UK degree classification grading system where it is broken down as follows:
First Class Honours – 70% and above equivalent to a 1st
Upper Second-Class Honours – 60-70% equivalent to a 2:1
Lower Second-Class Honours – 50-60% equivalent to a 2:2
Third Class Honours – 40-50%, equivalent to a 3rd
Design & Task
In terms of design, we have decided to use the ‘between participants’ design where each participant takes part in one condition. In this case, each participant will only answer their input for one chart type and that only. The decision was made since with a ‘within participants’ design the participants could end up improving with each trial run, due to familiarizing with the interaction with the experiment software, likely getting shorter times on the run with the second chart type, skewing results.
The task set out for each participant is to enter their answers on which they think which degree classification has the highest percentage in the chart displayed to them.
With training, the experiment will only take 5-8 minutes of each of the participant’s time.
We must present 10 trials of each chart type to our participants as per the coursework spec.
Therefore, the total number of participants in our experiment will be 10. This was decided as a reasonable amount as a problem that occurs when using this method is the need to recruit twice as many people with individual differences problems accompanied with it. To counter this problem, we suggested to ask 5 participants to take part in our voting experiment on questions on pie charts and another 5 participants to takes part on questions on bar charts.
In order for our participants to partake in this experiment, informed consent is required. This is completed using the Participant Information Sheet as found in the appendix of this report. This information sheet clearly indicates what we are asking from the potential participants, how long the experiment will roughly take and informing the user that they will completely remain anonymous with only recording the user’s responses.
Finally, they are explained that they are free to withdraw from the experiment at any time and no payment will be requested at all from them.
Upon sending out this information sheet, we have successfully received consent from 10 different participants to take part in our experiment.
The language we used to create this experiment was Python.
Figure 1 – Libraries we have used in our program.
Matplotlib – a plotting library that helped us make static visualizations in the forms of graphs
Matplotlib.colours – helped us change our colours of our charts
Numpy – a library allowing us to complete mathematical operations on arrays
Numpy Random – a numpy module which generate random numbers for our chart values
Time – a library that helps us with different time related operations using their functions
Upon running the python code in terminal, a greeting will be displayed. Followed by this will be some instructions informing the participants how to interact in this experiment. This can be seen below in Figure 2 where it outlies the instructions in the 4 steps.
Figure 2 – A screenshot of the terminal showing the greeting and instructions upon running the code
Next the program will ask each participant which chart group they are in and would like to be tested in. This would have been chosen in advance with each participant.
They could either enter in ‘A’ for Pie Charts or ‘B’ for Bar charts.
Once the participant enters either ‘A’ or ‘B’, the specific graph related to the input will be displayed as a pop-up window as shown in the Figure 3. In this case the participant has selected ‘A’ and a pie chart has been displayed.
On the other hand, we can see the window that pops up when the participant has selected ‘B’ in the terminal from Figure 4 below.