Intro to Collecting Data: Videos & Practice Problems
Intro to Collecting Data centers on choosing between an experiment and an observational study. An experiment is used when a researcher makes a change and compares outcomes between groups, such as applying a new condition to some subjects and not others. This approach is designed to study how a change affects a situation, so it supports conclusions about causation.
An observational study is used when the goal is to describe the current state of things without changing anything. Surveys and similar data collection methods fit this category when they simply record opinions, behaviors, or conditions as they already exist. Observational studies can reveal patterns, associations, or levels of interest, but they do not justify saying one factor caused another.
A key skill in collecting data is identifying the purpose of the study: if the question asks whether a change leads to an outcome, use an experiment; if the question asks what people currently think, feel, or do, use an observational study. This distinction helps determine what conclusions are valid from the data.
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
