Intro to Collecting Data: Videos & Practice Problems
Intro to Collecting Data focuses on choosing between an observational study and an experiment based on the question being asked. An observational study collects information about the current state of things without changing anything. It is used when the goal is to describe opinions, behaviors, or conditions as they already exist, such as learning how people currently feel or what they currently report.
An experiment is used when a researcher wants to see whether a change affects an outcome. In an experiment, a treatment or change is applied to one group and compared with a group that does not receive that change. This distinction matters because experiments can support causation, while observational studies can only show what is observed and cannot establish cause. A key idea in collecting data is matching the study design to the goal: use observation to measure the current state, and use experimentation to test whether a change leads to a result.
Introduction to Collecting Data
A regional store manager wants to test whether increasing store hours increases profits, so they randomly select half of their locations to stay open an extra hour later in the evenings and compare profits between stores at the end of the month. They notice that stores open later saw higher profits on average. Is this an experiment or an observational study? Can they determine the extra hours caused the increase in sales?
Observational study; no
Experiment; yes
Observational study; yes
Experiment; no
A store surveys its target demographic and learns that 86% of people would purchase the product they’ve been heavily advertising. Is this an experiment or an observational study? Can they conclude their current advertising strategy caused the high percentage of interest?
Experiment; yes
Experiment; no
Observational study; yes
Observational study; no
An office manager wants to determine how employees feel about their personal growth and professional achievement in the last quarter. Should they run an observational study or experiment?
Experiment
Observational study
Neither
Both
A software development company created a new app for fitness, and they want to determine if using the app can lead to weight loss and increased strength in customers. Should they run an observational study or experiment?
Observational study
Experiment
Survey
Case study
