Using scanning validation patterns

There are two types of scanning validation in Snap, ‘Spelling‘ and ‘Patterns‘.

• Spelling validation checks a response against a stored dictionary of words, and tries to match responses to words in the dictionary.
• Pattern validation depends on you creating the pattern of characters that you expect a response to be. It is most useful for responses such as dates, telephone number and zip codes.

There are different versions of spelling and pattern validation for handwritten and printed characters.

You can create one or more scanning validation patterns for each variable in your survey. Each pattern matches an expected response. You create a pattern by telling Snap how many of which characters you are expecting.

For example, you could create several scanning patterns for a phone number.

• A pattern that just expects the digits 0 – 9
• A pattern that expects a + as the first character
• A pattern that allows you to have the characters +, ( and ) as well as digits

The software would then check through each pattern in turn to see if it could match the scanned characters to the ones in the pattern, for example, it would assume that “l” was a one, rather than a lower case L.

1. Open the survey in Questionnaire mode.
2. Select the question that you wish to apply the pattern to (e.g. one asking “What is the phone number?”)
3. Press [Alt]+[Enter] to display the Variable Properties dialog.
4. Scroll to display the Scanning Validation property and change it from None to Pattern. This is the pattern for hand-written response.

   

5. Click OK to close the Variable Properties and then open the Variables window.
6. Locate the variable in the list which you set to Pattern and double click to open the Variable Details window.
7. Click on the Toggle Definitions icon and you will see Pattern selected in the Scanning Validation dropdown list.
8. Click on the button with 3 dots to open the Pattern Match List dialog which lists all existing patterns for this question (currently none).

   

1. Set a variable to use a pattern
2. Click [New…] on the Pattern Match List dialog to create a pattern.

   

3. The Pattern Match Details dialog opens. Use [Ctrl]+[C] to copy the sample pattern text that you require from the ‘Sample Scanning validation patterns’ table below step 10. Please note that there should be no line breaks.
4. Use [Ctrl]+[V] to paste the pattern text into the Pattern field.
5. Copy the text in the pattern to replace column if you wish to convert the response into a standard format. Paste this into the Replace With field.

   

6. Click [OK] to save the pattern.
7. Create any other patterns that you wish to use with on this variable (for example, add another phone number format). You can test multiple patterns by clicking [Test All] on the patterns list and then entering sample responses.
8. Once you have tested your patterns are working correctly, click [OK] to return to the Variable Details window.
9. Click to save the changes.

Sample scanning validation patterns

1. 1. 1. Set a variable to use a pattern.
      2. Click [New…] on the Pattern Match List dialog to create a pattern.

         

      3. The Pattern Match Details dialog opens. Click the button with 3 dots to the right of the Pattern field to open the Pattern Item dialog.

         

      4. Define the first element to match in your pattern. This will be two digits.Select Digit (0 to 9).

         

         Set the repetitions to be Exactly 2 in the Repetition area.
         Select Remember. This means that you will be able to replace parts of the pattern.

      5. Click [OK] to return to the Pattern Match Details dialog. The pattern item is described in the Description. It’s remembered as item \1 and looks for 2 digits.

         

      6. Now to insert a pattern item for a possible space. Put the cursor in the Pattern field at the end of the text and click the button with 3 dots again. Select Space.

         

         Set the repetitions to be 0 or more in the Repetition area.

      7. Click [OK] to save that part of your pattern.
      8. Now to define the letters in the pattern. Put the cursor in the Pattern field at the end of the text and click the button with dots again. Click “A”, hold down [Shift] and then click “Z” in the list of possible characters.

Set the repetitions to be Exactly 5 in the Repetition area.
Select Remember.

1. 1. 1. Click [OK] to save this part of your pattern. This part of the pattern is remembered as item \2 and looks for 5 characters.
      2. Enter \1\2 in the Replace With field of the Pattern Match Details dialog. The \1 refers to your first remembered pattern item and the \2 refers to the second remembered pattern. Any spaces are discarded.
      3. Enter a sample user ID in the Test field. Any spaces that separate the numbers from the letters will be removed in the Replace field. This shows what would happen to scanned text in the survey. The Replace text will be stored in Snap.

         

      4. Click [OK] to save your pattern.

If you want to use this pattern on other variables, you can copy the pattern definition text and paste it into a new pattern as described in Option A: Apply a sample pattern.