Question

coffee stations in offices often just ask users to leave money in a tray to pay for their coffee, but many people cheat. on some days, researchers at newcastle university replaced the picture of flowers on the wall behind the coffee station with a picture of staring eyes. they found that the average contribution increased significantly above the well - established standard when people felt they were being watched, even though the eyes were patently not real. complete parts a through c below.
a) was this a survey, an observational study, or an experiment?
this was ▼ because the researchers ▼

Explanation:

To determine the type of study:

• A survey collects data via questions/self - reports.
• An observational study observes without intervention.
• An experiment involves manipulating a variable (here, the picture behind the coffee station: changing from flowers to staring eyes) to see its effect on the outcome (average contribution). The researchers manipulated the independent variable (the picture) to observe the change in the dependent variable (contribution amount). So this is an experiment.

Answer:

This was an experiment because the researchers manipulated the variable (changed the picture behind the coffee station) to observe its effect on the average contribution.