Tips & Tricks

Minimize the verification effort

Do you carry out your paper-based surveys with verification, i.e. with manual visual correction of the insecurely read crosses? And do you often notice that you only have to confirm the suggestions made by the system, because the crosses were basically recognized correctly, but the fill levels are borderline, as shown in the following example?

Then you should absolutely get an overview of the average degrees of blackening of your scans to avoid unnecessary manual
effort.

The verification menu itself provides a useful tool with the overview of the fill levels. Here you can display the fill levels of the individual answer boxes of your scanned questionnaire sequence and check whether your scans fulfill the blackening required by EvaSys to ensure secure reading.

Where do I find the fill level?

Open „Verification“ and go to „Sequence View“. You will be offered to download a PDF with your scanned sheets in the „Fill levels“ column. The boxes in which blackening was detected are highlighted by yellow frames. There is a small number on the right side, which indicates the blackness percentage per answer.

How can I export the data?

For a complete overview, you can also export the fill levels as a CSV file. However, this function must first be enabled in the configuration in the „Maintenance“ section.

When enabled, the sequence view in the Verifier offers one CSV file per sequence with fill level percentage per question:

And what do I do with the information?

EvaSys works with questionnaires based on preset percentage limits, which determine whether a box is marked as secure, marked as insecure, non-marked, or treated as revised.

When numerous answers appear in the Verification, which just have to be confirmed, it is often the case because they are in the insecure reading range between 15% and 25% filling. Insecure marks can occur if participants cross the margin extremely strongly and there checkbox is filled to a comparatively little extent. If these, however, appear as overfilled, this is more a sign that your scanner is scanning the sheets too brightly and the contrast is insufficient to ensure secure reading. In that case, multifunction devices are often difficult to configure.

So, if you find that many of the answers are in the insecure reading range, you should act, rather than be satisfied with high level of verification effort. There are many possibilities here:

Try to reduce the brightness in the scanner driver or in the multifunction device settings, so that the scan as a whole gets a little darker. If in doubt, ask your IT staff to help you with the adjustment.

If the scanner cannot be configured any better, you can easily adjust the reading thresholds in EvaSys. To do this, you can overwrite the default values in the Scan Station settings in the „VividForms Reader“ tab and save them. For example, you could adjust the value for the maximum fill level of 25% to the percentage you are using (e.g., to 20%). This should significantly reduce the verification effort.

Whichever of the options you choose, our Support team will be happy to help you optimize your paper processing. In any case, you should not be satisfied with poor detection rates.

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