Scientific skills Flashcards
Describe the differences between quantitative and qualitative data
Qualitative data is descriptions e.g. colour and is represented with a bar graph as the data is discontinuous.
Quantitative data is numerical data e.g. 10 seconds and is represented as a line graph or histogram as it is continuous data.
Define independent variable
The independent variable is a factor that is changed or manipulated in an experiment to determine it’s effect on the dependent variable.
Define dependent variable
The dependent variable is measured to determine if the change or manipulation of the independent variable had any effect.
Define controlled variable
A controlled variable is one that is kept constant throughout the experiment.
Define reproducibility
Reproducibility is the closeness of results between a different experiment testing the same thing carried out by a different experimenter.
Define accuracy
The accuracy of a measurement relates to how close it is to the ‘true’ value of the quantity being measured.
Define precision
how closely a set of measurement values agree with each other.
How do you improve accuracy?
improve the measuring tool that is used to measure the dependent variable or collecting quantitative data instead of qualitative data.
How do you improve repeatability?
More repeats
Define repeatability
Repeatability is the closeness of results between the same experiment carried out by the same experimenter.
Write out the collection method scaffold.
There will be two ….
In the experimental group………… will be changed by ………………….
Add …… to a test tube.
Add…..
Add….
The ……………..will be measured by ……………………after
All other variables will be kept the same e.g. ………………………
Repeat the above for the other ….*not relevant if it is a all or nothing.
For the control group repeat the above but with no ……………….
Repeat the experiment ………….
If ……………. then …………………
Define control group
Factor affecting change has been removed, to provide a baseline of a comparison to the experimental group
