Collecting data Flashcards
What are the two variables scientists use in experiments
Independent variable (explanatory)
Dependent variable (response)
What is the independent variable
What you change in the experiment
What is the dependent varaible
What is effected in the experiment
What is extraneous varaibles
The researcher is not interested in these but it could effect the experiment so need to be controlled.
When can you assume the data from an experiment is valid and reliable
When the replicated results are similar
What are the 2 types of experiments
Controlled experiments
Uncontrolled experiments
Where are laboratory experiments conducted
In a controlled environment
What are the explanatory and response variables and the advantages and disadvantages of this investigation:
To investigate the effects of sunlight on plant colour, plants are exposed to sunlight for varying lengths of time.
Explanatory variable: length of time in sunlight
Response variables: difference in colour of plant
Advantages: easy to replicate, can control extraneous variables such as change in weather
Disadvantages: plants may react differently in a controlled environment compared with real-life growing conditions
What two types of experiments are uncontrolled experiments
Field experiments
Natural experiments
What are field experiments and where are they carried out
They are carried out in an everyday (uncontrolled) environment. The researcher sets up the situation and variables are controlled
What are the explanatory and response variables and the advantages and disadvantages of this investigation:
To investigate a new treatment for arthritis, the mobility of a sample of people is assessed before the treatment and then again after the treatment
Explanatory variable: new treatment
Response variable: difference in mobility
Advantages: more likely to reflect real-time behaviour
Disadvantages: cannot control extraneous variables e.g how active a person is at home and what effect that might have on mobility
What are natural experiments and where are they carried out
They are carried out in an everyday (uncontrolled) environment. The researcher has no control over any of the variables
What are the explanatory and response variables and the advantages and disadvantages of this investigation:
To investigate how a reduction in speed limit effects the number of car accidents on a road, the number of accidents per year on the road before the reduction is compared with the number per year after the reduction.
Explanatory variable: speed variable
Response variable: number of accidents
Advantages: more likely to reflect real-life behaviour
Disadvantages: cannot control any variables, harder to replicate the study
Why is it important to check data
To ensure it is consistent and accurate, otherwise your results may be invalid.
What can collected data contain
Outliers and anomalous data
