define the term statistics.
broadly getting “information” from data
define the term statistic.
- one numeric summary or one piece of information (may be numerical or non-numerical)
- summarizes one aspect of a data set or sample
what are descriptive statistics? what is the purpose of them?
- summarize information from a particular data set or sample
- only describe the sample
what are inferential statistics? what is the purpose of them?
- inference or infer –> so describing the larger population based on a sample
- make a conclusion about the larger population based on a smaller sample
define the term “population”. does this go with parameter or statistic?
- group of all the individuals you are studying
- whole population, everyone in a category
- goes with parameter
define the term “sample”. does this go with parameter or statistic?
- the set or part of the population where the data is collected from
- goes with statistic
what does the term “parameter” mean?
- value that summarizes some aspect of the population
- would be like the minimum, maximum, range, average
what does the term “statistic” mean when discussing samples?
the values that summarizes some aspect of the sample
what are statistics used for?
to relate them to the parameter in order to make a conclusion about the population
what are the methods for collecting data (aka a sample)?
- observational study
- designed experiment
what is an observational study?
- observe data or values or behaviour in the sample, for these you do not really need a special/specific method of collecting data
- observing data that already exists
what is a designed experiment?
- apply some type of treatment or experiment to the subjects and see how they respond
- primarily related to the relationship between a statistic and a parameter (connects them)
what are the two types of conclusions we can reach from a statistical study?
- population inferences
- causal claims
what are population inferences? what is needed random assignment or random selection?
- statistic or conclusion represents the population
- where statistic applies and connects to the parameter
- random selection
what are causal claims? what is needed random assignment or random selection?
- cause and effect (x causes y)
- random assignment
what does the term census mean?
- census would be like asking everyone in the population, not just a sample
define “simple random sampling”
- everyone has an equal chance to get in
- this is called a procedure
define “simple random sample”
- sample that came from simple random sampling
- this is a result
what are the two types of random sampling?
- sampling with replacement
- sampling without replacement
what does it mean if sampling with replacement occurs?
- any member of the population can be selected more than once (duplicates that occur)
- like a card getting picked, then put back into the deck and picking another card
what does it mean if sampling with replacement occurs?
- a member of the population can be selected at most once (duplicates cannot occur)
- so card gets picked then taken out of the deck, so it cannot be picked again
order of select individuals can either matter or not matter, what do we say in general about order in this class?
- in general that order does not matter
