Knowledge Base

Pie Chart

A Pie Chart shows for each parameter that you selected the proportion of the analysis time it was the dominant one (for facial expressions) or it was active (for Action Units) aggregated over the participants that you selected. In the above Pie Chart 'Happy' was the dominant facial expression for 41% of the analyzed time and 'Neutral' for 37% of the time. When you move over the chart with your mouse pointer you can also see the percentages for the other facial expressions. For instance, 'Sad' was the dominant facial expression for 0.158 (= 15.8%) of the analyzed time.

Box Plot

A Box Plot shows the minimum value (the lowest data point of the error bar), Q1 (first quartile) and Q3 (third quartile) (the borders of the box) and the median (Q2) for each parameter that you selected. When you move over the plot with your mouse pointer, you can see the values for Q1, Q2 and Q3.

Notes

• A quartile is the percentage of participants that shows this or a lower expression intensity. So if the first quartile (Q1, or 25th quartile) of the facial expression Happy is 0.3, this means that 25 percent of the participants has an intensity of Happy of maximally 0.3.
• The individual participants represent the samples. Hence, if you have five participants with three analyses each, the box plots are based on five samples.
• The quartiles are calculated with N + 1 Basis interpolation, which is also used in the statistical program SPSS. If the sample size is lower than 3, the first quartile (25th quartile) is the same as the minimum and the third quartile (75th quartile) is the same as the maximum value, which is also the same as in SPSS.

Bar Chart

A Bar Chart shows the values of the parameters you selected, aggregated over your selected participants and aggregated over time. When you move over the chart with your mouse pointer you can see the value for each parameter.

Circumplex Model

A Circumplex Model describes emotions in the form of a heatmap in a two-dimensional circular space, containing arousal on the vertical axis and valence on the horizontal axis. The center of the circle represents a neutral valence and a medium level of arousal. The Circumplex Model is based on the data of the participants that you selected.

The Circumplex Model is only available if you scored stimuli or event markers in your project.

The chart below shows the Circumplex Model for the five test participants in the 'FaceReader sample project - Two stimuli'. The data that are taken into account are those of the time period when the test participants were watching the 'Twins eating' stimulus. You can visualize another Circumplex Model, select the 'Frying insects' stimulus and compare the two plots.

The color of the heatmap is based on the percentage of time the affect that was most present occurred. This percentage of time (37% in the plot below) is set as the maximum and is colored red.

The Circumplex Model in FaceReader is based on the model described by Russel (1980).

Source: FaceReader 10 Reference Manual (Help), Noldus Information Technology