Steekproeven
aselecte steekproef
random random
cluster steekproef
Er worden groepen(clusters) gekozen om te onderzoeken/vergelijken en elk sample in deze groep word onderzocht.
gestratificeerde steekproef
alle samples worden ingedeeld in groepen(klasse) op basis van gemeenschappelijke eigenschappen en vervolgens worden er een random aantal samples gekozen per klasse.z
Opdrachten
1.2.8 a) no, it influenced the outcome by adding fertilizer. b) The study does not name all the variables and differences in said variables. like sun time and relative intensity on the other side of the garden. and also the amount of water given wasnt specified c) it was already a blind experiment because the plants dont know what they got. the researchers know what they gave the plants, so it wasnt a double blind
1.2.9 its not the religious service that improves ones ‘health’, but rather being in a large crowd with different pathogens could lead to an active immune system. making it strong and keeping it stronger for longer.
1.3.1 a) cluster steekproef b) aselect steekproef c) gestratificeerde steekproef d) aselect steekproef e) gestratificeerde steekproef
1.3.2 a) I. people in nightclubs are extrovert and usually don’t have social anxiety II. asking at a wider variety of places. on the streets at comiccons. b) I. rain water is purer and possibly less poluted II. make the samples match the ratio between sunny and rainy days in that area c) I. seems like a large space for only 20 trees. chances are that no or not enough shrubby trees will be found to accurately represent the distribution II. more trees