# Labeling Required and Optional Form Fields Test

Page: https://alidemirbas.com.tr/en/lab/ab-test-library/tests/labeling-required-and-optional-form-fields-test

## Hypothesis

If every field is marked as required or optional under one consistent rule, shoppers may no longer have to guess which fields they can skip. That could cut required-field errors and raise the form completion rate.

## When to run this test

Form analytics with required fields left blank, visitors who stall on an optional field and leave, or support contacts asking which information is needed are signs that field status in the checkout form is unclear. With clear labels, required-field errors should drop as visitors skip optional fields and submit the form. Match every label to the fields the backend actually requires before launch; if drop-offs come from confusing error messages, look at those first.

## Primary metric

**Form completion rate**: Compare successful submissions among visitors who see the form.

## Other metrics

- **Required-field error rate**: Track errors caused by missing required fields or invalid entries.
- **Form completion time**: Compare time from form start to successful submission.
- **Field-level abandonment**: Review the last field interacted with by visitors who leave without completing the form.
- **Form-related support rate**: Track support requests about filling in the form or understanding a field.

## What to check before and during the test

- **Labels**: Use one consistent rule to mark each field as required or optional.
- **Keep constant**: Keep field count, order and validation rules unchanged.
- **Errors**: Track errors caused by required fields left blank.
- **Mobile**: Make sure labels do not truncate field names on narrow screens.
- **Separate comparisons**: Test an asterisk versus written labels, or different label placement, separately.

## What to watch when reading the result

- The form completion rate settles this test. Required-field error rate and field-level abandonment only explain where a difference comes from; if errors fall but the completion rate does not change, that is not enough reason to ship the labels.
- What you measure belongs to the marking rule you tested and this checkout form. Show the labels in the same style as the rest of the form, since a mismatched style makes it hard to tell whether the labels or the visual break caused the difference. Look at mobile and desktop results on their own, and save asterisks versus written labels for a separate test.
- If few visitors see the form, a small difference can take a long time to detect. Before launch, enter today's form completion rate and the relative lift you care about in the [sample size calculator](https://alidemirbas.com.tr/en/calculators/sample-size-calculator); if the sample per variant it returns is large next to the form's traffic, you will not see that effect in a reasonable time. When the gap stays unclear, use form completion time and form-related support rate as context, not as the basis for the decision.

## Frequently Asked Questions

### How should required and optional fields be marked?

Use one consistent rule and label each field accurately. Do not mark a backend-required field as optional. Keep labeling consistent with the rest of the form.

### Which other metrics help explain form completion?

Use valid form completion as the primary outcome. Required-field errors, field-level abandonment, completion time and related support contacts provide diagnostic evidence. Reduced errors alone do not prove reduced uncertainty.

### Should I use an asterisk or a written label?

Written required or optional labels can be clearer. If using an asterisk, explain it before the form and associate it with the correct field. Do not rely on color alone. Compare the two labeling approaches separately if needed.