> ## Documentation Index
> Fetch the complete documentation index at: https://help.honestly.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Can I compare the results of different surveys?

> When results from different surveys can be compared, what happens to your existing trends when you merge two surveys, and how to compare them side by side anyway.

Are you planning a follow-up survey, or do you want to merge two surveys into one and still keep an eye on the results of previous years? Whether that works depends on which questions the surveys use.

### The basic rule: results are compared per question

The dashboard evaluates results per question, not per question text. Two surveys can therefore only be compared automatically, for example in a trend chart or across survey periods, if they use **the same questions**.

A question with identical wording that was created anew is a different question for Honestly. This also applies to:

* questions you add from the same question template
* questions from the Honestly Engagement or Pulse questionnaire when you create a new survey for them
* duplicated questions

Two different questions cannot be linked or merged afterwards.

### How to keep the same questions

There are exactly two ways for a survey to use the same questions as an earlier one:

* **Restart the same survey.** You adjust the existing survey and start a new survey period with **Create a new survey period**. [How can I reactivate a survey I have used before?](/help/surveys/reactivate) explains how.
* **Create a new survey with "Reuse existing".** Under **Surveys**, click **Create survey**, choose **Reuse existing** and then pick the original survey under **Survey to copy**.

When you reuse a survey, the new survey keeps using the questions of the original survey. This has three consequences:

* The questions in the new survey are locked. You cannot edit them there.
* Changes to the questions of the original survey apply to every survey that reuses them.
* Responses, dashboards and historical results are not copied. The new survey starts without responses of its own, but can be evaluated together with the original survey.

Questions you add to a survey are always new questions and have no past values.

### Example: merging two surveys

Say you have so far run a survey A (for example on health) and a survey B (for example on satisfaction), and from now on you only want to send out one survey. You have three options:

| Approach | What happens to your trends |
| - | - |
| Restart survey A and add the questions from B | The trend for the questions from A continues. The added questions are new and start without past values. |
| Create a completely new survey | There is no automatic trend to A or B. All questions start without past values. |
| Keep running A and B separately (restart or reuse) | Both trends are preserved. Your employees keep filling in two surveys. |

If the trend of one of the two surveys matters most to you, restart that survey and add the questions of the other one.

### Comparing different questions side by side

Even if the old and the new question are different questions, you can show their results side by side:

1. Add a new chart to your dashboard.
2. Select both the old and the new question.
3. Choose **Score** as the chart type.
4. Under **Split by**, choose **Survey**.

The chart then shows a separate value for each survey. This is a side-by-side comparison, not a continuous trend line: in a trend chart, each question remains a series of its own.

<Note>
  If you leave **Split by** on **None**, the chart combines the responses to all selected questions into one value. To compare them, you need the split by **Survey**.
</Note>

### Our recommendation

* Keep using questions you want to keep comparing, rather than deleting them or creating them again.
* [Hide](/help/surveys/hide-question) questions you no longer need instead of deleting them. That way their past results are preserved. [What happens when I delete a question?](/help/surveys/delete-question-effects) explains what deleting does.
* If you send the same survey to different groups or regions, [survey properties](/help/surveys/survey-properties-benefits) help you filter the results later.

### Related articles

* [How can I reactivate a survey I have used before?](/help/surveys/reactivate)
* [How can I hide a question in my survey if I no longer need it/don't need it at the moment?](/help/surveys/hide-question)
* [What happens when I delete a question?](/help/surveys/delete-question-effects)
* [How do I create a trend chart?](/help/dashboard/create-trend-chart)
* [How can I compare the results of different employee groups in my dashboard?](/help/dashboard/compare-groups)
* [What are survey properties, and how can they help me?](/help/surveys/survey-properties-benefits)