Experiment or Correlation

Is stem 1...

• A correlation

• An experiment

2. Stem 1 is an experiment as it seeks to establish if there is an associative relationship between the type of interview and the accuracy of eyewitness testimony. One reason it's an experiment is that there is direct manipulation of the ​ (a)   , which is the type of interview. In correlations, there's no manipulation. Furthermore, the researcher is only measuring one ​ (b)   , which is the accuracy score, whilst in a correlation the researcher would measure more than one​ (c)   . Additionally, the researcher could have ​ (d)   the participants to be in either condition, which isn't possible in a correlation (as this lacks any conditions). Finally, the researcher could have worked out the average for each condition, and could then have presented this in a ​ (e)   , showing which condition had a higher accuracy score.

• independent variable
• dependent variable
• co-variable
• randomly allocated
• bar chart
• standardized

Stem 2 is...

• An experiment

• A correlation

Stem 2 is a correlation as the researcher does not manipulate either of the two variables (resting heart rate or average hours of sleep each night), indicating there is no ​ (a)   . Furthermore, the researcher measures the two variables (each of these is called a ​ (b)   ), rather than just measuring a single ​ (c)   , as would happen in an experiment. Additionally, the researcher could present the data for this study on a ​ (d)   with resting heart rate on one axis and average hours of sleep on the other. This type of graph would be innapropriate for an experiment. A ​ (e)   could be used to describe the strength and nature of the correlation between these variables.

• independent variable
• co-variable
• dependent variable
• scattergram
• correlation co-efficient
• bar chart

Is stem 3...

• An experiment

• A correlation

Stem 3 is an experiment rather than a correlation because of the way the variables are being investigated. More specificallly...[explain how variables are investigated in an experiment compared to a correlation. Then explain how this applies to the stem. Refer to concepts like indepndent variable, dependent variable and co-variables]

Answer explanation

Stem 3 is an experiment because of the way the variables are being investigated. More specificallly in an experiment the researcher directly manipulates one variable, called the indepndent varaible, and measures another, called the depndent variable. In contrast, in correlations, reearchers do not manipualet any variables, but instead measure two co-variables. This applies to the stem as the researcher manipulated which two tasks the particiapnts completed (the IV) and measured how many seconds it took to complete (the DV), rather than measuring two co-variables.

Is stem 4...

• An experiment

• A correlation

Stem 4 is a correlation rather than an experiment because of the way the variables are being investigated. More specificallly...[explain how variables are investigated in a correlation compaed to an experiment. Then explain how this applies to the stem. Refer to concepts like indepndent variable, dependent variable and co-variables]

Answer explanation

Stem 4 is a correlation rather than an experiment because of the way the variables are being investigated. More specificallly, in a correlattion researchers measure two co-variables, whilst in an experiment researchers only measure one variable (the DV) and manipulate the other (the IV). This applies to the stem as the resarchers are measuring two co-variables Intelligence and happiness) without manipulating either (indicating there's no IV).

Is stem 5...

• A correlation

• An experiment

Stem 5 is an experiment rather than a correlation because of the way the variables are being investigated. More specificallly...[explain how variables are investigated in an experiment compared to a correlation. Then explain how this applies to the stem. Refer to concepts like indepndent variable, dependent variable and co-variables]

Answer explanation

Stem 5 is an experiment rather than a correlation because of the way the variables are being investigated. More specificallly., in an experiment, researchers manipulate one variable (the IV) and meausre another (the DV), whereas in a correlation they only measure two co-variables. This applies to the stem as the researhers manipulate thebackground noise (the IV) and measure the performance score (the DV), rather than measuring two co-variables.