Chapter 7 - The Experimental Research Strategy

Question 1

What is the goal of the experimental research strategy?

Answer 1

to establish the existence of a cause-and-effect relationship between two variables

Question 2

To rule out the possibility of a coincidental relationship, an experiment must…

Answer 2

show that changes in one variable are directly responsible for causing changes in the second variable

Question 3

What are the following four basic elements that an experimental study contains?

Answer 3

Manipulation, Measurement, Comparison, and Control

Question 4

The research MANIPULATES one variable by…

Answer 4

changing its value to create a set of two or more treatment conditions

Question 5

A second variable is MEASURED for a group of participants to…

Answer 5

obtain a set of scores in each treatment condition

Question 6

All other variables are CONTROLLED to be sure that they…

Answer 6

do not influence the two variables being examined

Question 7

What is an independent variable?

Answer 7

A variable that is manipulated by creating a set of treatment conditions

Question 8

What are the specific conditions that are used in an experiment called?

Answer 8

Levels

Question 9

What is a dependent variable?

Answer 9

A variable that is measured in each of the treatment conditions.

Question 10

All other variables that are not the independent or dependant variables are called what?

Answer 10

Extranous variables

Question 11

What does an experiment attempt to demonstrate?`

Answer 11

That changing one variable (independent V) causes changes in a second variable (dependent V).

Question 12

The general purpose of the experimental research strategy can be broken down into TWO specific goals:

Answer 12

1. demonstrate that the “cause” happens before the “effect” occurs–manipulates the IV and then observes the DV to see if it also changes
2. to show that one specific variable is responsible for changes in another variable–most show that changes are not caused by an extraneous variable

Question 13

Dr. Jones is interested in studying how indoor lighting can influence people’s moods during the winter. A sample of 100 households is selected. Fifty of the homes are randomly assigned to the bright-light condition where Dr. Jones replaces all the lights with 100-watt bulbs. In the other 50 houses, all the lights are changed to 60-watt bulbs. After two months, Dr. Jones measured the level of depression of the people living in the houses. In this example, how many dependent variables are there?

Answer 13

1 - the level of depression

Question 14

How do studies using the experimental research strategy differ from other types of research?

Answer 14

Only experiments can demonstrate a cause-and-effect relationship between variables

Question 15

What are the 2 elements of experimental research that are unique?

Answer 15

Manipulation & Control

Question 16

If you wanted to investigate the effect of temperature (IV) on appetite (DV) what would you manipulate?

Answer 16

You would manipulate the room temperature
EX.60 degrees for one treatment condition, change it to 70 degrees for another condition, and change it again to 80 degrees for the third condition

Question 17

In an experiment, what is the purpose for manipulating the independent variable?

Answer 17

It helps establish the direction of the relationship and it helps eliminate the third-variable problem

Question 18

Research indicates the people who suffer from depression also tend to experience insomnia. However, it is unclear whether the depression causes insomnia or the lack of sleep causes depression. What problem is demonstrated by this example?

Answer 18

The directionality problem

Question 19

What is a confounding variable?

Answer 19

A third variable that is allowed to change systematically along with the two variables being studied

Question 20

A study is done to determine whether children prefer sweetened or unsweetened cereal. For one group, the researcher uses a box of colourful sweetened cereal, and for the other group, a box of tan-coloured unsweetened cereal. Results showed that the kids ate more of the sweetened colourful cereal and therefore prefer the sweetened cereal. What is the potential confounding variable?

Answer 20

It is impossible to tell whether the preference for the colourful sweetened cereal is caused by the colour or the sweetness.

Question 21

What is the difference between extraneous and confounding variables?

Answer 21

There are thousands of other variables that exist within any experiment, an extraneous variable becomes a confounding variable only if it influences the dependent variable

Question 22

In order to establish a relationship between two variables, it is necessary to eliminate the possible influence of…

Answer 22

Confounding variables

Question 23

What characteristic is necessary for an extraneous variable to become a confounding variable?

Answer 23

It must change systematically when the independent variable is changed.