Both run card sorts and tree tests. Where they differ is who checks every response, and what a year of research costs you. Here is the side-by-side, with every claim about Optimal Workshop linked to its own pages.
This is the biggest difference. Optimal’s recruited panel has automatic checks and free replacements, and that is worth having. Past that, most of the judging is yours: sorting by time taken and deciding who looks careless. SortedResearch does that judging for you, on every response, whoever sent the participant.
| Quality layer | SortedResearch | Optimal Workshop |
|---|---|---|
| Fraud and duplicates, before the study | ✓Our panel partner turns away fraud, duplicates and screener fails before they reach you. | ✓Says it runs “multi-layer fraud prevention” on its recruited panel.6 |
| Bots and tampering | ✓Every answer validated on the server, rate limits, and one completion per device for up to 180 days. | ?Claims “automated bot traffic elimination”. No mechanism is described in its help centre.6 |
| Speeding, while it happens | ✓A participant racing through is asked to slow down, then asked again, then the session ends. All four study types. | –Not documented. |
| Speeders, after they finish | ✓Automatic on every response, judged against how long your cards or tasks take to read. | ~Recruited card-sort participants are flagged for being too fast. For your own participants, and on tree tests, you sort by time and exclude people yourself.7,8 |
| Tapping the same spot every time | ✓Side-bias and position-bias checks on pairwise and Best–Worst. Left and right are randomised, so a one-sided run stands out. | –No straightlining check documented. |
| Lazy sorts | ✓One giant pile, every card on its own, too few groups, or groups that mirror the shuffled order. | ✓Excludes people who put every card in one group, or every card in its own group.7 |
| Sorting without reading the cards | ✓Checks whether cards plainly about the same thing ended up together. A sort a random shuffle would match is rejected. | –Not documented. |
| Careless tree tests | ✓Eleven checks, including never opening a menu, skipping without trying, the same answer on every task, and clicking around one branch. | ~Manual: sort by time taken and exclude anyone who looks too quick.8 |
| Borderline responses | ✓Not thrown away. Ranked to the top of your list, each with a plain-English reason, so you make the call quickly. | ~Flagged people are excluded, and the final decision is left to you.5 |
| What a bad response costs you | ✓Nothing. It is rejected, refunded and replaced automatically. | ✓Free replacements. The help centre allows 30 days to ask, while the Terms say you must tell them within 5 days.5,4 |
| If the order under-fills | ✓The difference is refunded to your card automatically when you close the order. | –Participant credits are non-refundable and expire after 12 months.4 |
Check counts: eleven on Findability, nine on a card sort, five each on pairwise and Best–Worst. “Not documented” means we could not find it on Optimal’s website or help centre on 2 October 2026, not that it cannot exist.
Optimal’s entry plan is sold by the year and counts your studies. Ours is sold by the month and does not.
$2,388 is $199 × 12. Neither figure includes recruited participants, which both charge for separately.
| Plans and participants | SortedResearch | Optimal Workshop |
|---|---|---|
| Trying it first | One trial study, up to 10 participants, no card | No free plan. A 7-day trial shows results from your first 2 participants.2,3 |
| Billing | Monthly, or annual with 2 months free | Annual only on Starter and Enterprise2 |
| Studies | Unlimited on any paid plan | 5 a year on Starter, extra studies bought in bundles1 |
| Seats | 1 on Individual, 3 on Team, custom on Enterprise | Unlimited1 |
| Recruited participants | From $5 per completed response. The price is shown before you pay, with no minimum. | Bought with credits; one standard participant costs 1 credit. The dollar price of a credit is not published.1 |
| Do you need a subscription to buy participants? | No. You can buy an audience before you subscribe. | Yes. Credits require a paid subscription.4 |
| Hard-to-reach audiences | The live price updates as you edit the screener, before you pay | “Niche” requests (under 10% incidence, for example) can carry extra fees per participant4 |
| Paid for a response you didn’t get | Refunded automatically | Credits are non-refundable, and expire 12 months after purchase4 |
Optimal covers more of the UX toolkit. SortedResearch goes further on structure and priority: how people group your ideas, whether they can find them, and which of them matter most.
| Method | SortedResearch | Optimal Workshop |
|---|---|---|
| Card sorting | ✓Open, closed and hybrid, built for the phone, readable at 60 cards and beyond | ✓Open, closed and hybrid9 |
| Tree testing | ✓Findability: a confidence range on every task, every task on one map, and an Adaptive Tree that proposes the fix round by round | ✓Success, directness, paths and pietrees10 |
| Pairwise comparison | ✓Importance and satisfaction, plotted on an opportunity matrix | –Not offered as a method on their site |
| Best–Worst (MaxDiff) | ✓Ranks a list of 20 or 30 items on a 0–100 scale with a must-have line | –Not offered as a method on their site. Ranking questions and closed sorts are the nearest. |
| One study feeding the next | ✓Turn a finished card sort into a pairwise, Best–Worst or Findability study in one click | –Not documented |
| AI-written report | ✓Graham writes a client-ready report: headline, opportunities, next steps, and an honest note on data quality | ~AI themes from questionnaire answers, plus summaries for interviews and usability tests11 |
| First-click, surveys, prototype tests, interviews | –Not offered | ✓All offered12 |
We would rather you picked the right tool. Optimal is the stronger choice if:
If your work is concepts, needs, benefits and navigation, and you want each response checked for you, SortedResearch is built for it.
All pages read on 2 October 2026. SortedResearch facts come from our pricing page and help centre. Optimal Workshop is a trademark of its owner. SortedResearch is not affiliated with or endorsed by Optimal Workshop.
Try one study to see how it works. Every response is checked, and you only pay for the ones that pass.