key skills Flashcards
Define aim?
Purpose of investigation identified.
what is Alternative
Hypothesis?
A hypothesis stating that THERE IS a
relationship between the two variables being investigated.
whats a hypothesis?
Arising from the aim, it is testable prediction
that suggests a relationship between
independent and dependent variables.
Must be: a short statement a prediction gives cause and effect states dependent/independent variables
what is quantitative Data, discrete and continuous?
Numerical.
Discrete: finite number of possible values. e.g. whole numbers
Continuous: infinite possible values
can be any number, e.g. 4.777
Define the term Independent
Variable?
The variable that is deliberately changed in
an experiment, as it does not change due to
other variables.
e.g. light on a plant
The one you are not measuring
What is Qualitative Data?
All data that isn’t numerical, e.g. diaries,
personal testimonies
define the term dependent
Variable?
The variable that will change in line with the
independent variable does.
e.g. growth of a plant - changes as light
changes
The one you are measuring.
what is Primary Data?
data collected by the people doing the
investigation.
what is null Hypothesis?
A hypothesis stating that there is NO
relationship between the two variables being investigated.
what is secondary Data?
Already collected by people not doing the
investigation, but the information remains
relevant for the investigation
Explain Sampling; it’s methods (random, systemic and stratified), and it’s pros and cons?
Testing out a hypothesis on a small section
of the total population.
(The larger the sample size, the more reliable the results.)
Random: avoids bias
Systematic: sample population selected by
patterns, e.g. every 10th person
Stratified: taking cross section of population
Pros: cheaper; less time consuming
Cons: may give inaccurate results for the total population
what is bias?
Encouraging one outcome over another.
what is a pilot survey?
A trial run of a survey, which aims to bring to the fore any problems with the survey before it is conducted on a larger scale.
what dose calibrated mean?
To check and make any necessary
adjustments to a piece of equipment to
ensure its accuracy.
explain the different types of average?
Mean: the total of all values divided by the total number of values
- the average average
Mode: the value with the highest frequency (can be more than one answer)
- the most often
Median: the value in the middle, after the data has been sorted in ascending order (if the number lies between two entries, add the two entries together and divide by two)
- the middle number
