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## High school statistics

### Course: High school statistics>Unit 5

Lesson 1: Introduction to planning a study

# Types of studies

AP.STATS:
DAT‑2 (EU)
,
DAT‑2.A (LO)
,
DAT‑2.A.3 (EK)
,
DAT‑2.A.4 (EK)
CCSS.Math:
We can distinguish between experiments and observational studies, and further describe types of observational studies: retrospective, prospective, and sample surveys. Created by Sal Khan.

## Want to join the conversation?

• Hi everyone,

In this video Sal classifies different types of observational studies (retrospective, prospective and sample study) based on the type of temporal data they are based on (past or present).

E.g. using historic data in an observational study, results in a Retrospective Observational Study.

Although this perspective is useful in distinguishing observational studies, it does not seem to be complete. This is because both prospective and sample observational studies are based on current (i.e. present) data.

Therefore, if we are only told that a study uses present/current data, we cannot judge if this observational study is a sample or prospective one.

What's something that can be added to this explanation to make distinguishing between sample and prospective more definitive and exhaustive?

Thanks!

/ Eduardo
• What is the difference between an observational study and experiment studies??
(1 vote)
• mr khan academy my tescher caser help!11
(1 vote)
• 😮‍💨😃😁
(1 vote)
• You mentioned Taxonomy. What does that have to do with the topic?
(1 vote)
• taxonomy is a kind of fancy word for classification which Sal is doing right here
(1 vote)