scientific processes Flashcards
what is an aim?
a precise statement on why a study is taking place/what is being studied
what is a hypothesis?
a precise testable prediction of what is expected to happen
what are the 2 types of hypothesis?
-experimental/alternative - predicts differences in the DV are beyond just chance, experimental is used only for the experimental hypothesis, alternative is used for anything else
-null hypothesis - predicts the IV won’t affect the DV, any differences are due to chance
what are the 2 types of experimental/alternative hypothesis?
-directional (one-tailed) - predicts the direction
-non-directional (two-tailed) - predicts a change will happen but doesn’t predict the direction
what is sampling?
selecting participants to represent a wider population
what are the 5 types of sampling?
-random
-opportunity
-volunteer
-systematic
-stratified
what is random sampling?
each member of the population has an equal chance of being selected
what are the strengths of random sampling?
-unbiased selection
-generalisation
what are the weaknesses of random sampling?
-impractical
-not representative
what is opportunity sampling?
selecting participants who are available and willing to take part
what are the strengths of opportunity sampling?
-ease of formation
-natural experiments
what are the weaknesses of opportunity sampling?
-unrepresentative
-self-selection
what is volunteer (self-selected) sampling?
people volunteer to participate, often by replying to adverts
what are the strengths of volunteer sampling?
-ease of formation
-less chance of the ‘screw you’ phenomenon
what are the weaknesses of volunteer sampling?
-unrepresentative
-demand characteristics
