# Words for single point in time versus multiple points in time

In the context of describing how data is collected for research, I am looking for words that distinguish data that represent events that occur all at one single point in time versus events that occur at two or more points in time.

The closest idea I have come up with is "cross-sectional data" versus "panel or longitudinal data". However, there is a subtle difference that is important to me. Cross-sectional and longitudinal data refer to when the data is collected, not to what the underlying events represent. Let me use an example of surveying people about their impressions of a product that they are considering buying. Suppose they are surveyed in month 1 about their impressions of the product before they buy it and then they are surveyed again in month 2 to know whether they bought the product or not; that is considered longitudinal data because they are surveyed at two distinct points in time. But if in another study people are surveyed only once in month 1 to know their impressions about the product and their intention to buy it, that is considered cross-sectional data because they are surveyed only at one point in time.

However, I am interested in the second scenario because even though there is only one data collection, the questions asked represent two distinct events that span different points in time: 1) their present impressions of the product and 2) their future intention to purchase the product. I am specifically interested in a word that, regardless of if the data collection is cross-sectional or longitudinal, captures this idea of two or more events at distinct points in time implied in the survey questions.

The best I can think of is "instantaneous" to represent a single event and "multitaneous" to represent two or more distinct events. The problem, though, is that "multitaneous" is not an English word. I would appreciate any suggestions.

• It’s a survey with two questions. Most surveys have several questions. Commented Sep 13, 2022 at 23:44
• Wrong metaphor. You're right about individual points in time, but they don't contrast with multiple-points, but with continuous stretches of time, like distances. You're moving from zero dimensions to one. English has words like since that refer to lengths of time defined by starting points, and ago that refer to points in time defined by lengths. They can even be used together, like functions: He's lived here [since [16 years ago]]. Commented Sep 14, 2022 at 0:12