S1 - Data Collection Flashcards
What is qualitative data?
-Non-numerical data which describes
qualities, rather than measurements
What is quantitative data?
-Data which is counted or measured,
giving a numerical value
What is discrete data?
-Data which can be counted or takes
specific values
What is continuous data?
-Data which can be measured on a scale
What is raw data?
-Information which has not been
ordered or processed in any way
What is primary data?
-Data collected by or for the person
who will be using it
What is secondary data?
-Data from another source, perhaps
for a different reason
What is an advantage to primary data?
-It is trustworthy. You know how and
by whom it was collected, and how
recent it is.
What are two advantages to secondary data?
- Cheap
- Easy to obtain
What are two disadvantages to secondary data?
- You don’t know who collected it
- Out of date
What is an explanatory or
independent variable?
-The variable controlled in an
experiment
What is a response or dependent
variable?
-A variable which results from an
experiment
What are upper and lower bounds?
-Upper bound = largest possible
value
-Lower bound = lowest possible value
During a survey, what is the
population?
-Everything or everybody taking part
in the survey
What is a pilot survey?
-A small survey carried out to help
identify problems or limits before
doing a full survey
Why are tally marks useful in recording data?
-Quicker to write than a word or
number
-Grouping into fives makes them
easier to process
What are two methods of collecting data
for an opinion poll?
- Personal interviews
- Telephone surveys
- Postal surveys
- Shoppers surveys
Explain the reason for a control
group in a statistical experiment.
-Gives a standard for comparison of
changes in the experimental group
What is the difference between a
census and a sample?
-A census obtains information from
the whole population. A sample
obtains information from part of the
population.
What is the difference between a
population and a sample?
-A population is the whole group you
wish to study. A sample is a smaller
representation of the whole
population.
What is a sampling frame?
-All items in the population from
which a sample can be drawn
Describe a simple random sampling method.
-Any method where each member of the population has an equal chance of being chosen: -Draw names from a hat -Assign each item a number and use a random number generator
What is the advantage of stratified
sampling?
-Ensures proportionate
representation of different groups
within the population
Describe quota sampling.
-A sample is chosen based on given
specifications or instructions
What is systematic sampling?
-All items in the population are listed
in a given order, then every nth item
from a random start point is chosen
What is cluster sampling?
-The population is divided into
smaller groups, then one or more
groups is chosen
What is a standard population?
-1000 people who represent the
whole population, found by stratified
sampling
What conditions need to be true of the population when using capture-recapture sampling?
-Constant population when both
samples are taken
-The first marked sample must have
mixed well with the whole population
