Your stimulus is what respondents see when they're evaluating your idea. Getting it right - clear enough to understand, but not so leading that it biases the result - is one of the most important things you can do before launching a test.
This guide covers what you can include as stimulus, how to write your description, and specific guidance by test type.
What counts as stimulus?
Stimulus is the combination of what respondents see and read when evaluating your concept. On Ideally, this can include:
A description - up to 700 characters of text
An image - product shots, pack designs, storyboard frames, moodboards, creative executions
A video - TVCs, animatics, explainers, or rough cuts
An audio file
Click here for further information on acceptable image, video and audio formats.
You can use one or a combination. The key is that together they give respondents enough to react to — without telling them how to react.
Writing your description
The description field supports up to 700 characters. How you use it depends on what you're testing.
For product and concept tests, use the description to communicate the product's unique value and benefits in consumer-friendly language. You can include:
What the product does and why it's different
Flavours, pack sizes, or bundle options to bring the concept to life
Usage occasion or target audience — only if it helps set the scene, and only if your study doesn't already ask about need states or usage occasions
For communication tests (ads, TVCs, scripts, storyboards), keep the description minimal. Respondents won't separate the description from the stimulus — they'll read both together. That means if you summarise your message in the description, you're testing your summary, not your creative.
If you need to include anything, limit it to a short scene setup:
"You're about to see an idea we're currently developing. It's still in draft form, so please focus on the message and sentiment rather than the execution."
For pack tests, a description isn't always needed. Use the introduction text field to give respondents any necessary context, and toggle on the pack test option so the questions are framed around look and feel.
Guidance by test type
Idea tests
Test type | What to include in the description |
New product / concept | Value prop, key features, usage occasion, target audience (if needed) |
Pack test | Objective pack features only (e.g. size, portions, resealability). Avoid terms like "single use" or "multiple use" — these frame how respondents interpret the pack |
New flavour or variant | Factual description only. No comparisons to the parent product |
Creative | Short description of the creative idea. Avoid summarising the intended message |
Launch test | Pack shot + 1–2 sentence product description. Recommend profiling for category purchasers in the last 12 months |
Communication tests
Test type | What to include | Level of detail |
Functional message | The message going to market, as it will appear | Direct — you're testing comprehension and likability |
Creative territory | Territory name/theme line. Use intro text to frame the early-stage nature of the work | Minimal |
Script | Script copy with clear labels for voiceover, scene, and action | As needed for comprehension |
Storyboard / moodboard | 1–4 images to convey tonality. Add a short description of what the film would show, ending with a CTA if applicable | Minimal — let the images lead |
TVC / online video | Scene context only | Minimal |
Static ads (OOH, social, display) | Placement context only (e.g. "this will appear on a billboard") | Not required — the image should speak for itself |
Concepts with mechanics
When your concept has a clear process or system to communicate — a loyalty programme, a subscription model, a multi-step product — the image itself should do the explaining. Structure your stimulus image around three elements:
Headline — one sentence summarising the main benefit (recommended font size: 18–20pt)
How it works — 2–3 short bullet points covering the key mechanics. Keep it to a small number of elements; don't try to list everything (minimum font size: 14pt)
Outcome — one sentence explaining the benefit or impact
If you include a text description beneath the image, keep it short. Use it to clarify how the concept works — not to introduce new storytelling elements.
To set this up in Ideally:
Upload your image containing the headline, "how it works", and outcome
Add a short text description if needed (optional)
Name your idea and click Save
Images can be landscape or portrait. Respondents can zoom in.
Stimulus Mock-Up Example
Strategic territories
For early-stage concepts where you're testing a direction rather than a finished product, your stimulus should communicate the territory clearly without over-specifying the execution. Keep the image focused on what the proposition stands for, and use any text description to clarify what it's for — not to tell respondents what to think about it.
To set this up in Ideally:
Upload your image
Add a short text description if needed (optional) - we recommend keeping it short. Use it to clarify what the proposition is for, rather than introducing additional storytelling elements.
Name your idea and click Save
Stimulus mock-up examples
Rebranding and repackaging tests
How you set up stimulus for these tests depends on what you're trying to learn.
Rebranding:
Testing new branding on its own — don't show old branding, don't mention the rebrand. You want natural impressions without comparison bias.
Measuring recognition of new vs old — show both in a split sample. Mention the change using neutral phrasing if needed.
Assessing response to brand change — show both, and mention the rebrand briefly and factually.
Repackaging:
Testing appeal of the new pack — don't include the old pack, and don't mention the change. You want to understand impressions of the new design on its own.
Comparing old vs new directly — show both (split sample or side-by-side), and mention the change in neutral terms.
Testing sustainability or functional benefits — mention the change briefly and factually to help respondents assess whether the new pack communicates its value.
Image and video tips
Images:
Use clean, well-lit product or pack shots with a neutral background where possible
For storyboards, include 1–4 frames to convey tonality. Keep imagery and narrative separate to avoid clutter
Avoid including copy or claims in images that you're separately testing in the description
Videos:
Animatics, rough cuts, and work-in-progress executions are fine — just set expectations in your intro text
For scripts and explainers, pair the written script with a visual where you can to aid comprehension
Using the introduction text field
The introduction text appears above your stimulus and is a useful place to:
Set expectations for early-stage or rough creative ("This is still in development — focus on the message, not the finish")
Provide category context for unfamiliar products
Direct respondents on what to focus on for pack tests