Frequently Asked Questions - TeleForm Choice Fields

Choice fields are a highly-used type of field in TeleForm. They use OMR (Optical Mark Recognition) technology to detect ticks/checks/marks to determine whether or not a box is ticked. Typical examples of choice fields are:

• Yes/No responses
• Gender responses
• Satisfaction scoring (unsatisfied, neutral, satisfied)

A choice field in TeleForm can have any number of choices which can be arranged freely on the page. TeleForm has a variety of different styles for you to choose from:

• Bubbles: these are small circles or ovals. Expected inputs are full shading, crosses or ticks.
• Boxes: the small squares or rectangles have expected inputs of crosses or ticks.
• Underlines: less frequently used, TeleForm displays a small horizontal line on which the expected input is a tick.
• Responses: these types expect the choice text to be circled. These were common a few years ago for Title style fields (Mr, Mrs, Miss, Ms, etc.). Less frequently used these days.
• Brackets: very seldom used. TeleForm will print a pair of brackets on the page with the expected input being a tick or a line between them.

The order of the different types in the list above is by popularity of use, and also by preference of use. It is much better, from a recognition accuracy point of view to use bubbles and boxes than responses and brackets. The response field can be particularly problematic as it becomes unclear to some users whether they should circle their chosen response, or whether they should cross out the inappropriate ones. In addition, a response field requires the user to circle reasonably neatly close to the text.

For these reasons, a closed shape (such as a bubble or box) will always perform better and more accurately than an open shape (such as a response or bracket).

How does TeleForm recognise whether a choice is ticked or not?

Every time TeleForm needs to process a choice field, it will look at each of the choices and literally calculate how much of the choice actually contains ink. It returns this calculation as a percentage. For a bubble choice that has been completely filled in, this will then return a 100% result. For a neighboring choice that is completely empty, a result of 0% is returned. Such extremes are easy when determining if something is ticked or not. For percentages between these extremes, TeleForm uses a scale with thresholds. The default values for these thresholds are 40% and 25% (called Mark Fill High and Mark Fill Low respectively).

• If the percentage of ink within the choices is calculated to be more than or equal to the Mark Fill High (40%) then the choice is considered to be definitely marked and TeleForm needn't ask the Verifier operator for confirmation (unless more than one mark is detected for a single-choice response).
• If the percentage of ink within the choices is calculated to be less than the Mark Fill Low (25%) then the choice is considered to be definitely empty, and TeleForm needn't ask the Verifier to confirm (unless the choice field is set up as "Entry Required").
• If the percentage of ink is detected to be within the Mark Fill High and Mark Fill Low values, then TeleForm will consider the choice to be ticked, but will ask for confirmation from the Verifier operator.

Example marks in bubbles or boxes	Percentage	Decision
	99% (MORE than 40%)	DEFINITELY FILLED
	41% (MORE than 40%)	DEFINITELY FILLED
	28% (BETWEEN 25% and 40%)	FILLED BUT UNSURE
	24% (LESS than 25%)	DEFINITELY NOT FILLED
	1% (LESS than 25%)	DEFINITELY NOT FILLED

The thresholds of 25% and 40% are TeleForm's default settings. As can be seen from the table above, they aren't necessarily the best settings as the 21% mark has been considered to be definitely not filled. The thresholds are generally designed for fields that are either filled in completely/crossed, or completely empty. Generally, tick marks are very popular in the UK which don't generally present very high percentages, particularly if they aren't well formed within the bubbles/boxes.

For this reason, it is a good idea to adjust the thresholds slightly. The actual figures to use will vary wildly on the types of form, scanned or faxed images, etc. You must run your own testing to determine the best values. However, ePC generally recommend adjusting the Mark Fill High from 40% to 30%, and the Mark Fill Low from 25% to 20%

It is also best to change these settings on a form by form basis such that all fields on the form have the same settings.
Designer-->Form menu-->Properties-->Form Level Settings tab-->OMR thresholds-->Form Level:

What happens if a single-choice field has too many marks?

If a field is set up for single-choice only, TeleForm will only let one choice value to be exported to the database. In the event that multiple marks are detected (as in the example below), TeleForm will automatically push the form to the Verifier so that a user may decide which of the options is the intended choice.

In this particular case, it is likely that the form user crossed box B initially, then changed their mind before scribbling over the initial response and then crossed D. It would be unsafe for TeleForm to assume either B or D. In this case, the form will be automatically sent to the Verifier for human-intervention.

How are choice values exported to a database?

For single-choice fields (where only a single choice is acceptable), data exported to the database uses the "Store in database as" value.

For multiple-choice fields there are three ways of exporting data:

• Single Column Variable: Multiple values are exported to a single field, separated by commas
• Single Column Fixed: Multiple values are exported to a single field, however, all values are separated by commas regardless of whether they are ticked or not, but only ticked values are visible (see example below)
• Separate Columns: Multiple ticked values in a field are exported into separate columns, with 1=ticked, 0=unticked.

Example	Single Column Variable	Single Column Fixed	Separate Columns
	Colour	Colour ,,	Red Green Blue 0 0 0
	Colour Green	Colour ,Green,	Red Green Blue 0 1 0
	Colour Red,Blue	Colour Red,,Blue	Red Green Blue 1 0 1
	Colour Red,Green,Blue	Colour Red,Green,Blue	Red Green Blue 1 1 1