Knowledge Base

Analyze the Data

Data Preparation

Track Editing

Choose Acquisition > Edit Tracks. You can fix tracking errors and swap back nose-points and tail-points that have been swapped in tracking. Normally you do not need to edit your data.

Track Smoothing

Choose Acquisition > Track Smoothing Profile. Select one or both options to remove noise and artifacts due to for example body wobbling. For more information, see Smooth the Tracks in the EthoVision XT Help.

Select Data for Analysis

Choose Analysis > Data Profile. The data you select on this screen will be analyzed or visualized.

• Analyze data per zone: In the Result box, click Settings and select Results per zone. Use this function for example to analyze the velocity of the subject in the different zones.
• Analyze some tracks, not others: Under Filter, choose one of the variables available. For example, Treatment to analyze Treated animals only. Insert the box in the Data profile sequence.
• Analyze segments based on behavior: Under Nesting, choose one of the options. For example, to select all data points when the subject was moving, choose Movement. Insert the box in the Data profile sequence.
• Analyze tracks split in equal duration segments: In the Result box, click Settings and select Time bins. Use this function for example to analyze a 10-minute recording in ten segments of one minute each.
• Create groups of tracks and compare results: Under Common Elements, click Result and add a Result box. You can link each Result box with a specific Filter. This way you can compare the results of different selections, or visualize groups of tracks that result from different treatments, etc.

For more information, see the EthoVision XT Help.

Visualize the Data

You can visualize your tracks in three ways:

Plot the Tracks

Choose Analysis > Results > Plot Tracks. You can view your tracks on a still image of the background. Tracks can be shown in different colors according to the values of independent variables (for example, blue for animals treated with saline and red for drug-treated animals). Sample points can be shown in different colors according to the values of dependent variables, for example red when the animal was moving fast.

To set the track colors, in the Track Plot Settings pane, click the Colors tab.

Plot Integrated Data

Choose Analysis > Results > Plot Integrated Data. Look at a track with the video file in the background. When you plot integrated data you can also view Time Event plots of your independent variables. Just like with plotting tracks, you can show tracks or sample points in different colors.

Plot Heatmaps

Choose Analysis > Results > Plot Heatmaps. Make heatmaps of the location of your animals during the tracks.

For more information, see Visualize Data in the EthoVision XT Help.

Calculate the Statistics

General Procedure

1. Choose Analysis > Analysis Profile > New. Select the variables you are interested in. For information about the variables suggested, see the chapter about the test of your choice and the EthoVision XT Help.
2. Choose Analysis > Results > Statistics & Charts, then click Calculate. The Trial Statistics tab shows the results per trial. The Group Statistics tab shows the statistics and charts from the results over all trials or the groups defined in your Data profile.

Adjust the Table Layout (Optional)

Sometimes you need to adjust the layout of your results table, for example to export the results to a statistics software. Click the Layout button on the toolbar and specify which headers should be on the rows and which on the columns. For details and examples, search for table layout in the EthoVision XT Help.

Batch Calculations

It is also possible to carry out multiple calculations at once with different filters, data profiles or analysis profiles. To do so:

1. In the Statistics & Charts window, click Batch.
2. Select the profiles from the lists and click Add.
3. Repeat the previous step for other combinations.
4. Click Calculate. Choose the profiles from the lists on the toolbar to view the analysis result for that combination.

For more information, see Calculate Statistics in the EthoVision XT Help.

Advanced Analysis with JavaScript Custom Variables

In the Analysis profile you can create fully custom dependent variables with JavaScript code. With JavaScript you have an almost endless range of possibilities to extract information from your tracks. JavaScript variables can be of type continuous, event, or state.

See JavaScript in the EthoVision XT Help.

Note: If you are not familiar with programming, Noldus can create custom analysis variables for you. Please contact Noldus for information.

Export the Results

To find out if your independent variables (like treatment, dose, etc.) have a significant effect on the dependent variables, you can export your data to a statistical package.

1. Choose Analysis > Export > Statistics.
2. Choose Trial Statistics or Group Statistics.

You can also export the raw track data. Choose Analysis > Export > Raw Data.

Source: EthoVision XT 18 - Application Manual, Noldus Information Technology