Chapter 1 Review Flashcards
Is a way of reasoning, along with collection of os and methods, designed to help us understand the world
Statistics (the discipline)
A collection of methods for planning experiments, obtaining data, and then organizing, summarizing,presenting analyzing, and drawing conclusion based on the data
Statistics
Are particular calculations made from data
Statistics (plural)
Values with a context (datum is singular form)
Data
The complete collection of data from EVERY element in a population
Census
A sub-collection of elements drawn from a population (must be collected randomly to be useful)
Sample
Observations (such as measurements, genders, and survey responses) that have been collected
Data
A numerical measurement describing some characteristics of population
Parameter
A numerical measurement describing some characteristic of a sample
Statistic
Values that answer questions about the quantity or amount (with units) of what is being measured(example:income, height, weight)
Quantitative data
(Qualitative data) can be separated into different categories that are often distinguished by some nonnumeric characteristic (examples:sex,race, zip codes, ethnicity)
Categorical data
Result from infinitely many possible values that correspond to some continuous scale that covers a range of values without gaps, interruptions, or jumps (often time has units of measure attached)(examples: the amount of rainfall in Zelie this past month)
Continuous Data
Characterized by data that consist of names, labels, or categories only (cannot be arranged in ordering scheme)
Nominal
Can be arranged in some order, but the differences between the data values either cannot be determined or are meaningless
Ordinal
Similar to the ordinal level, but the difference between any TWO data values is MEANINGFUL. However, there is NO NATURAL ZERO starting point (where none of the quantity is present)
Interval
Similar to interval, but HAD a NATURAL ZERO starting point (where zero indicates none of the quantity is present)
Ratio
Are used to determine the tv shows we arch and the products we buy
Poll Results
Provide better products at lower cost by statistical control tools, such as control charts
Manufacturers
Are controlled through analyses designed to anticipate epidemics
Diseases
Are protected through regulations and laws that react to statistical estimates of changing population size
Endangered species
(Voluntary responses sample) is one in which respondents themselves decide whether to be included
Self-selected survey
The 9 abuses of statistics
- Bad samples
- Small samples
- Loaded questions
- Misleading graphs
- Pictographs
- Precise numbers
- Distorted percentages
- Partial pictures
- Deliberate distortions
Observe an measure specific characteristics, but we don’t attempt to MODIFY the subject being studied (no treatment)
Observational study
A TREATMENT IS APPLIED to observe its effects on the subjects
Experiment
Mathematical or physical MODEL used to reproduce a situation ( when it is too dangerous)
Simulation
Investigation of characteristics of a population ( asking questions and collecting data)
Survey
A FAUX treatment that looks like the real treatment
Placebo
Occurs when an untreated subject incorrectly believes that he/se is receiving a treatment and reports an improvement in symptoms
Placebo effect
A technique in which the subject doesn’t know whether he/she is receiving a treatment or placebo
Blinding
The RESEARCHER KNEW which subject received which treatment, but the SUBJECT DID NOT KNOW
Single blind
NEITHER the researcher nor the subject knows who reviews the placebo or treatment
Double blind
A GROUP of subjects that are SIMILAR to test effectiveness of one or more treatments (similar background, gender)
Block
This is a way to assign subjects to BLOCKS through RANDOM selection (eliminates bias)
Randomized design
Experimental units are carefully chosen so that the SUBJECT IN EACH BLOCK are SIMILAR in the WAYS THAT ARE IMPORTANT
Controlled design
Occur in an experiment when the effects from two or more variables cannot be distinguished from each other
Confounding
Make sure your sample is LARGE enough, however, an extremely large sample is not necessarily a good sample (no magic number) (when in doubt use 30)
Sample size
Helps to confirm results by repeating the experiment
Replication
Collect data in an appropriate way, other wise your data will be useless
Randomization
Members of the population are selected in a way that each has an EQUAL chance of being selected
Random Sample
Sampling schemes that combine several methods
Multistage Samples
The difference between a sample result and the true population result; such as an error result from chance sample fluctuations (it just happened)
Sample Error
Occurs when the sample data are incorrectly collected,recorded or analyzed (you did it)
Non-Sampling Error
Study five sampling techniques
- Systematic sampling
- Stratified sampling
- Cluster sampling
- Simple random sample (SRS)
- Convince sampling
The complete collection I all elements or subjects to be studied
Population
Result when a number of possible values is either a finite number or a “countable number”
Discrete Data
RANDOMLY select a starting point through a RANDOM # generator, calculator or software, and take every kth SUBJET of the population
Systematic Sampling
We SUB-DIVIDE the population into at least TWO different subgroup that share the SAME CHARACTERISTICS, then draw a sample from each stratum
Stratified Sampling
First DIVIDE the population area into sections, then RANDOMLY select some of these clusters, and then choose ALL members from those selected clusters
Cluster Sampling
n subjects are selected in a way that every possible sample of size n has the same chance of being chosen
Simple Random Sample (SRS)
A researcher chooses a sample that is convenient or easy for them to access
Convenience Sampling
Two quantitative methods
Interval and ratio
Two categorical methods
Nominal and ordinal
4 steps in designing and experiment
Identify pop and objective
Collect sample
Random procedure
Analyze data and form conclusions
4 types of methods of data collection
Observation
Experimental
Simulation
Survey
