Question

Observation Types: Cross-Section or Time-Series?

Question 2.a. Consider a survey that took over a year to collect and compile. That survey looked at selling prices of all houses in Cherry Creek, Colorado over the past year. An observation in the data table is a house. Does the resulting data table contain a cross-section or a time-series? Why do you say so? (Hint: if in doubt, get out pencil and paper and construct a hypothetical version of the data table.)

Question 2.b. A variable measures, to the closest minute, the time-of-day over the last month that one specific client entered a website. The variable has multiple observations because the client entered the website more than once over the past month. Would this be a cross-section or a time-series? Why do you say so? (Hint: footnotes are important, even if they're footnotes.)

Question 2.c. My data table contains number of queries sent to a help desk each day of the week (weekdays only) over the past year. The help desk is only open Monday through Friday. Does the data table contain a cross-section or time-series? Why do you say so? (Hint #1: footnotes can be important, even if they are footnotes. Hint #2: if in doubt, get out pencil and paper and construct a hypothetical version of the data table.)

Answer 1

The cross-section data is a type of data which is collected from different individuals or groups at a single point in time and the time-series data is a type of data which is collected at a time period for the same thing.

Question 2a.

The survey data is cross-section data because it is collected for different houses.

Question 2b.

The client data is a time-series data because it is collected at a fixed time period that is to the closest minute, time-of-day.

Question 2c.

The queries data is a time-series data because it is collected for the number of queries on weekdays only.