Study Methods

A list of students is randomly generated from the school database.  Information for every student is entered into the database, and each student has an equally likely chance of being selected.  The students selected are asked how much time they spend on household chores each week

• Observational study
• Controlled experiment
• Survey

The local librarian collects data about the types of books that are checked out so that she can place a new book order accordingly.  She records the type of book checked out by every other person each day for three weeks.

• Observational study
• controlled experiment
• survey

A gardener tests a new plant food by planting seeds from the same package in the same soil and location.  Each plant is given the same amount of water, but one plant is given food and the other plant is given no food at all.  He records the growth and flowering rates of each plant.

• observational study
• controlled experiment
• survey