ELAN offers a possibility to compute some statistics of the tiers. Click on
View > Annotations Statistics and select a tier in the
dialog window:
Figure 2.120. Annotations Statistics
If you wish the Annotations tab to show the statistics of a
dependent tier, uncheck Show only root tiers
and select it. Uncheck the
next option if you want ELAN to count all contiguous annotations with the same value
as
1.
The observation period is the interval between the beginning of
the first annotation of all tiers and the end of the last annotation of all tiers.
If
you want ELAN to use the total media duration, just check Use media duration as
observation period
.
The Annotations tab shows the following information:
- Annotation
- Occurrences: the number of occurrences (contiguous annotations containing the
same value count as only one occurrence if the relevant option is checked).
- Frequency: the frequency defined as the number of occurrences divided by the
observation period.
- Average Duration: the average duration defined as the total duration of the
annotations with the same value divided by the number of occurrences.
- Time Ratio: the time ratio defined as the total duration of the annotations
containing the same value divided by the observation period.
- Latency: the latency defined as the time interval between the beginning of the
observation period and the first occurrence of an annotation.
The Annotations II tab shows:
- Annotation
- Occurrences: the number of occurrences.
- Minimal Duration: the duration of the shortest (in time) annotation.
- Maximal Duration: the duration of the longest (in time) annotation.
- Average Duration: the average duration defined as the total duration of the
annotations with the same value divided by the number of occurrences.
- Median Duration: the median duration defined as the duration that separates
the lower half of the annotation durations from the higher half.
- Annotation Duration Percentage: the ratio between the total duration of the
annotations and the total media duration expresses as a percentage.
- Latency: the latency defined as the time interval between the beginning of the
observation period and the first occurrence of an annotation.
In the Annotations II tab, contiguous annotations
with the same value are not counted as 1. The observation period is
the same as the media duration.
The Tiers tab shows:
Figure 2.121. Tiers statistics
- Tier: the name of a tier.
- Number of Annotations: the number of annotation on that tier.
- Minimal Duration: the minimal duration of an annotation on that tier.
- Maximal Duration: the maximal duration of an annotation on that tier.
- Average Duration: the average duration of the annotations on that tier.
- Median Duration: the median duration of the annotations on that tier.
- Total Annotation Duration: the total duration of all annotations on that
tier.
- Annotation Duration Percentage: the percentage of the total annotation
duration of the media duration on that tier.
- Latency: the time interval between the beginning of the observation period and
the first annotation on that tier.
The observation period on the
Tier tab is the interval between the begin and the end of the
media.
The statistics on the tabs Tier Type,
Participant, Annotator,
Language are similar to the statistics on the
Tiers tab except that they apply to tier type, participant,
annotator and content language respectively.
The information in the columns displayed on every tab can be sorted in different
ways. By clicking the header of the preferred column, the information below gets sorted.
This is done in an ascending order first, and subsequently toggling between ascending
and descending order. Saving the statistics will also output the selected sort order.
Figure 2.122. Sort order statistics
An annotation density plot visualizes the distribution of annotations (the
segmentation) over the media duration or over a selected time interval. The textual
annotation values are ignored.
Figure 2.123. An annotation density plot
There are a number of options to customize the visualization and the result can be
saved as an image. Apart from the usual tier selection options the following settings
are available:
- Limit to current selection the plot will be restricted to
the current time selection
- Tier column width the width in pixels available for the
tier names. Set to 0 to switch off tier names.
- Image width the width of the image in pixels
- Image height the height of the image in pixels
- Tier height the height of a tier layer in pixels
- Tier height - Fill when this box is checked the tier
height is calculated such that the entire height of the image is occupied by the
selected tier layers. A minimum height is applied, a message will be shown if the
tiers don't fit.
- Margin height the white space above and below each
colored band in pixels
- Include outlines when checked, grid lines will be drawn
to mark the boundaries between tiers
After making changes click the Update button to see the new
settings in effect. Click the Export button to show a
Save As window and save the result as a PNG
image.
Figure 2.124. The effect of unticking the Fill checkbox