experimental data Flashcards
the independent variable is…
CHANGE
the dependent variable…
MEASURE
the control variable…
things you keep the same
what is reliability?
experiments that give the same data
what is validity?
- experiments that give the same data (reliable)
- designed to be a fair test
what is accuracy? how do you improve it?
results that are true
improve it by making measurements more accurate eg by using different equipment like a ruler in mm instead of cm
what is precision?
the results are very similar to the mean average
eg results are 12, 14, 13 so the mean is 13 is PRECISE
results are 11, 17, 14 so the results are not
how do you improve reliability?
repeat the test
suggest some hazards of practicals:
- MICROORGANISMS - can be dangerous/make you ill
- FIRE eg bunsen burners
- CHEMICALS eg burning your skin, flammability
- ELECTRICITY with electrical equipment
suggest some ways of reducing hazards
- wear gloves
- wear goggles
- use a heat proof mat (fire)
sampling (eg quadrats)
- must be random
(because you can’t study every organism so the sample you take must be as close to the truth as possible, therefore choosing an area that is higher than normal will disrupt the results)
eg divide the area into a grid and then choose the coordinates out of a hat
ethical problems in experiments
- treat safely/humanely eg food, water, overcrowding
—> wild animals should be returned after the experiment to their habitat - should gain consent from humans
results that are abnormal are called…
anomalous
discrete vs continuous data
discrete - set groups of data eg shoe size or the number of siblings (because you can’t have half a person)
continuous - numerical data that can be any value (2.5 or 7453765) eg length or temperature
qualitative vs quantitive data
qualitative - in words eg favourite colour
quantitative - uses numbers
