Week 11 - The Experimental method, and Causalty

Question 1

What can looking at data variability help you with?

Answer 1

Identifying a causal relationship between variables

Question 2

If the systematic data variation is larger than the unsystematic variation

The equation is systematic variation / unsystematic variation

Answer 2

If systematic variation (i.e., the number on the top) is larger than the unsystematic variation (i.e., the number on the bottom), the answer must be greater than 1 because your numerator is larger than your denominator.

Ratio will be > 1

Question 3

The goal of unsystematic variation is…

Answer 3

To reduce unsystematic variation in the data

Question 4

in the experimental method:

Answer 4

• the experimenter manipulates the independent variable
• All confounding variables should be held constant
• Participants are randomly assigned to conditiolns

Question 5

Control over confounding variables in an experiment allows….

Answer 5

Ruling out alternative explanations for changes in the dependent variable

Question 6

Random allocation of participants to conditions avoids…..

Answer 6

Random allocation ensures participants with similar characteristics are evenly distributed across conditions,
avoiding assigning all people with the same traits to one condition. This increases internal validity, not external validity, and does not negate the control of confounding variables.

Question 7

Quasi experiments are carried out when:

Answer 7

Quasi-experiments are used when it is not possible to randomly allocate
participants to conditions. While they often have higher ecological validity,
this is not their defining feature. They differ from natural experiments, where independent variables cannot be manipulated, and are not specifically tied to having a limited number of cases.

Question 8

Field experiments are carried out to….

Answer 8

Increase ecological validity by being
conducted in natural settings. Unlike natural experiments, they allow manipulation of independent variables. Random allocation
may still be feasible, and the number of cases is not a defining
characteristic.

Question 9

Natural experiments are carried out when….

Answer 9

It is not possible to manipulate any of the
independent variables. They rely on naturally occurring variations and often aim to
increase ecological validity, but this is not their primary defining characteristic. The
inability to randomly allocate participants to conditions or the number of cases are
secondary considerations.

Question 10

Single case studies are carried out when…

Answer 10

There is only a limited number of cases available. This focus on a single instance provides detailed insights that might not be feasible in larger
studies. Manipulation of independent variables, ecological validity, or random allocation are
not defining characteristics of this method.