Sequential versus Monadic Testing

Sequential testing answers "Which is best?" Monadic testing answers "Is this good?"

Sequential Stimulus Exposure

Sequential exposure means one respondent will evaluate each of your stimulus in the same survey. Results in sequential testing can be influenced by the exposure effect respondents consciously or subconsciously compare each stimulus to the others they've seen.

Example

Three new chocolate bar concepts are being tested:

• If ideas A and B are weak and idea C is average, C is likely to score higher than it "deserves" because respondents are comparing it to weaker options.
• If ideas A and B are strong, idea C is likely to score lower, for the same reason, comparison, not absolute quality, drives the result.

When It Works Well

This comparative effect isn't necessarily a drawback. It's actually an advantage when:

• Your research question is "which one is best?" You want respondents to compare stimuli and choose based on everything they've seen.
• You're testing very similar stimuli. Small differences that wouldn't show up in a monadic test are more likely to surface in a sequential one — making it easier to support a business decision.

Additional Benefit

Sequential designs tend to be cheaper, since the same respondent can evaluate multiple stimuli in one survey, instead of running separate surveys for each (as monadic testing requires).

Monadic Stimulus Exposure

Monadic exposure means each respondent with evaluate only one of your stimuli for the entire survey. Monadic testing tends to be more reliable, since each respondent only evaluates one stimulus. Results for any given stimulus aren't affected by exposure to competing options.

Because there's no comparison at play, the data collected reflects a stimulus's performance in absolute terms rather than relative to others in the test. This makes monadic testing well suited to answering "is this good?"

When It Works Well

This absolute-measurement approach is an advantage when:

• Your research question is "is this good?" You want an untainted read on how a stimulus performs on its own, free from comparison effects.
• You need a benchmark. Results are typically compared against a norm built from many other stimuli tested the same way, giving you a consistent yardstick across studies.

Additional Consideration

Monadic designs tend to be more expensive, since each stimulus requires its own separate respondent sample, rather than reusing the same respondents across multiple stimuli.

Quick Comparison

What Zappi Solutions are Sequential or Monadic?