Decision Making
Online Grocery Task
Also called: simulated supermarket task, virtual grocery shopping task, online supermarket experiment
Compare shopping baskets under different prices, product labels and preset choices, with spending and basket totals.
4-7 minUntimed
Free to start: 10 free participants per account, then $0.99 per participant for academic research, or any yearly plan. Try it here first, with no account.
- Papers, 2021 to 2025
- 45
- Evidence grade
- D
- Registered clinical studies
- 1
− 0 packs +
− Packs: 1 +
What it measures
Records a shopping basket in a simulated online shop. Participants choose unbranded foods for a short list within a budget. Studies vary prices, nutrition or environmental labels, and preset baskets. Reports spending and basket totals.
Constructs
- Consumer choice
- Response to product information
- Budgeted decisions
Research uses
- Consumer decision research
- Food choice research
How the paradigm works
The Online Grocery Task records choices in a simulated shop. Participants fill a four-category list within a budget, choosing from 12 original unbranded products. They can add or remove whole packs and review the basket before finishing. The list stays visible. A comprehension question and a practice basket introduce the controls. Nothing is bought or delivered.
More about the paradigm
Studies can show nutrition labels, environmental labels, both or neither. Price settings apply a discount to the lowest-emission product in each category or a surcharge to higher-sugar packs. Starting baskets can be empty or contain the lowest-sugar or lowest-emission product in each category. All preset packs can be removed. A seed sets product order within categories. Prices and the budget can be scaled together for the study currency.
Scores
- Basket Spendingstudy currency
- Sum of price times packs in the completed basket.
- Compare the same products, price multiplier and currency
- Budget Remainingstudy currency
- Budget minus basket spending.
- Unused hypothetical budget
- Budget Used%
- Basket spending divided by the budget.
- Share of available spending
- Packs Chosencount
- Total packs in the basket, including repeated products.
- Quantity chosen
- Different Products Chosencount
- Products with at least one pack.
- Variety within the fixed shop
- List Categories Metcount
- Categories containing at least one pack.
- Four are required to finish
- Basket Energykcal
- Sum of the simulated energy values of the selected packs.
- These are study values, not actual dietary intake
- Basket Sugarg
- Sum of the simulated sugar values of the selected packs.
- These are study values, not actual dietary intake
- Basket Emissionsg CO2e
- Sum of the simulated emissions values of the selected packs.
- Hypothetical carbon dioxide equivalents
- Preset Packs Keptcount
- Number of preset packs present at checkout; removing and re-adding a pack counts as keeping it.
- Zero for an empty starting basket
- Basket Changescount
- Accepted additions and removals during shopping. Presets and blocked additions are excluded.
- Editing activity
- Shopping Timems
- Time from the shop opening until the participant finishes the basket.
- Includes browsing and review
- Comprehension Correctflag
- Whether the participant correctly said preset products can be removed.
- Describes understanding of the instructions
- Anticipationscount
- Completed baskets submitted in under 100 ms; these have no basket scores.
- Describes response timing
Use and evidence
45 papers from 2021 to 2025 name this task in their title or abstract, up 200% compared with 2016 to 2020. That ranks it 373 of 582 test families in our census. See the counts for every test.
Show the numbers
| Year | Papers |
|---|---|
| 2025 | 19 |
| 2024 | 3 |
| 2023 | 10 |
| 2022 | 6 |
| 2021 | 7 |
| 2020 | 3 |
| 2019 | 5 |
| 2018 | 1 |
| 2017 | 3 |
| 2016 | 3 |
| 2015 | 4 |
| 2014 | 3 |
| 2013 | 3 |
| 2012 | 2 |
| 2011 | 1 |
| 2010 | 2 |
| 2009 | 0 |
| 2008 | 0 |
| 2007 | 1 |
| 2006 | 1 |
| 2005 | 1 |
| 2004 | 2 |
| 2003 | 0 |
| 2002 | 1 |
| 2001 | 2 |
| 2000 | 0 |
Use grade D
30 to 99 papers from 2021 to 2025.
Evidence grade D
Little published measurement evidence found.
- Papers on test-retest reliability
- 0
- Papers on reliability or validity
- 4
- Registered clinical studies using it as an outcome
- 1
Measured on ConductCognition
Pooled across the studies that feed our platform norms, by device group. A figure needs 50 or more people.
No pooled figure yet.
Note on the counts: Original simulated shop; no retailer assets; hypothetical prices and product values; editable budgeted basket; no purchase or dietary advice..
How the grades work
Use: A is 1,000 or more papers from 2021 to 2025, B 300 to 999, C 100 to 299, D 30 to 99 and E fewer than 30. Evidence: A means at least 25 papers report its test-retest reliability and at least 25 registered clinical studies use it as an outcome; B, at least 8 test-retest papers, and either 5 registered clinical studies or 150 reliability or validity papers; C, at least 2 test-retest papers, 30 reliability or validity papers or 3 registered clinical studies; D, little published measurement evidence found. The counts measure use. They include every paper that names the task in its title or abstract. Grades describe the published research on this task, not ConductCognition's version of it.
Source: ConductCognition test census 0.39.0, counted 10 November 2026 from OpenAlex and ClinicalTrials.gov.
Task design
The trial sequence as the test runs in ConductCognition.
- Shop
- 12 original unbranded products in four categories: grains, protein foods, vegetables and drinks. Three products per category; prices and pack sizes always appear. The seed shuffles products within each category.
- Shopping list
- At least one pack from each category, with up to 3 packs of each product. The list stays visible. Participants can move between categories and edit the basket at review.
- Budget
- 20 study-currency units by default, configurable from 10 to 100. A multiplier of 0.1, 1, 10 or 100 scales every price and the budget together. Additions above budget are blocked.
- Labels
- None by default; nutrition, environmental impact or both can be shown. Nutrition gives energy and sugar per pack. Environmental labels give grams of CO2e per pack. Every value is hypothetical, written for this shop.
- Prices and presets
- Standard prices, 20% off the lowest-emission product in each category, or 20% extra for packs with at least 10 g sugar. Starting basket: empty, lowest sugar or lowest emissions. Preset packs are disclosed and removable.
- Practice
- One comprehension question with feedback, then add, remove and re-add a pack in a practice basket. No time limit. One completed shopping basket is scored.
- Scores
- Spending, remaining budget, budget share, total packs, different products, categories met, energy, sugar, emissions, preset packs kept, basket changes and shopping time.
An original browser basket following simulated-supermarket research. It uses our own products, prices, numerical labels and study values, rather than the VR shop, Agribalyse values or traffic-light labels used by Arrazat and colleagues. All four list categories must be filled to finish. Missing or invalid baskets have no spending score. Choices are hypothetical, with no real purchase, dietary advice or percentile output.
Quality checks
Each session is marked valid, needs review or invalid, with the reason, before you see its scores.
Shopping choices have no correct answer. Finishing the whole basket in under 200 ms invalidates. An incomplete basket or a missed comprehension question is flagged.
Why these rules
The task records spending and the composition of a simulated basket. Preferences are not accuracy scores and there are no individual percentiles.
No percentile. Scores and quality flags only.
Running this test
Settings you can change
| Setting | Standard | Allowed |
|---|---|---|
| Product labels | No labels (standard) | No labels (standard), Nutrition, Environmental impact, Both labels |
| Prices | Standard | Standard, 20% off the lowest-emission product in each category, 20% extra for packs with at least 10 g sugar |
| Starting basket | Empty (standard) | Empty (standard), Lowest-sugar product from each category, Lowest-emission product from each category |
| Budget before multiplier | 20 | 10 to 100 |
| Study currency | USD | USD, EUR, GBP, CAD, AUD, JPY, CNY, BRL, CHF, INR |
| Price multiplier | 1 | 0.1, 1, 10, 100 |
Yearly plans can change settings within these limits. Free and pay-as-you-go studies use the standard settings.
Need a setting this test does not have?
Devices and languages
- Untimed test: runs on desktops, laptops, tablets and phones. Participant devices
- Languages: English, Spanish, French, German, Italian, Portuguese (Brazil), Chinese (Simplified) and Japanese.
- Available on: Every plan, including the free plan.
- No percentile. Scores and quality flags only. How norms work
- Recruiting online? See the setup guides for Prolific, Sona Systems, CloudResearch Connect and Qualtrics.
Cite and describe
Participants completed the Online Grocery Task in a web browser (ConductCognition task version 1.0.0, scoring version 1.0.0; Arrazat et al., 2023), with the standard settings (product labels: No labels; prices: Standard; starting basket: Empty; budget before multiplier: 20; study currency: USD; price multiplier: 1). The main score was basket spending (sum of price times packs in the completed basket).
ConductCognition versions: task version 1.0.0, scoring version 1.0.0. Every export records the versions each session used, for a methods section.
- Arrazat, L., Chambaron, S., Arvisenet, G., Goisbault, I., Charrier, J.-C., Nicklaus, S., & Marty, L. (2023). Traffic-light front-of-pack environmental labelling across food categories triggers more environmentally friendly food choices: a randomised controlled trial in virtual reality supermarket. International Journal of Behavioral Nutrition and Physical Activity, 20(1), Article 7. https://doi.org/10.1186/s12966-023-01410-8
Source papers
Questions
How long does the Online Grocery Task take?
About 4 to 7 minutes, as listed in the test library.
What device does a participant need?
Untimed test: runs on desktops, laptops, tablets and phones. The browser must be Chrome, Edge, Firefox or Safari.
What scores does it produce?
Basket Spending, Budget Remaining, Budget Used, Packs Chosen, Different Products Chosen, List Categories Met, Basket Energy, Basket Sugar, Basket Emissions, Preset Packs Kept, Basket Changes, Shopping Time, Comprehension Correct and Anticipations. Each session is also marked valid, needs review or invalid, with the reason.
How widely is the Online Grocery Task used in research?
45 papers from 2021 to 2025 name it in their title or abstract, up 200% compared with 2016 to 2020. That ranks it 373 of 582 test families in the ConductCognition test census (use grade D). Source: ConductCognition test census 0.39.0, counted 10 November 2026 from OpenAlex and ClinicalTrials.gov.
How much reliability evidence does the Online Grocery Task have?
In the published research, 0 papers report its test-retest reliability and 1 registered clinical study uses it as an outcome (evidence grade D in the ConductCognition test census).
Does it report a percentile?
No. Scores and quality flags only.
Which settings can a researcher change?
Product labels (No labels (standard), Nutrition, Environmental impact, Both labels), prices (Standard, 20% off the lowest-emission product in each category, 20% extra for packs with at least 10 g sugar), starting basket (Empty (standard), Lowest-sugar product from each category, Lowest-emission product from each category), budget before multiplier (10 to 100), study currency (USD, EUR, GBP, CAD, AUD, JPY, CNY, BRL, CHF, INR) and price multiplier (0.1, 1, 10, 100). Settings can be changed on yearly plans; free and pay-as-you-go studies use the standard settings.
Which languages can participants use?
Participants can take this test in English, Spanish, French, German, Italian, Portuguese (Brazil), Chinese (Simplified) and Japanese, with its words in the same language. English is on every plan, and the other languages come with yearly plans. Have a native speaker read the machine-translated text before launch.
Is this a clinical test?
No. ConductCognition is for research use only. It runs, scores and exports the test; clinical interpretation is outside the platform.
Every test: the full test list.
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