speculation about how to explain facts or observations
To avoid biases, what type of hypothesis do you test?
What type of question must be posed with every experiment?
A hypothesis (best guess) is always written as a
A research question tends to be..
A general inquiry that is considered "nondiectional" (does not say whether there is an adverse effect through association)
A hypothesis should always be __________ rather than just relying on basic associations
What are the five steps to testing a null hypothesis for statistical significance
- 1) Develop a null and alternate hypothesis
- 2) Establish the appropriate alpha level
- 3) perform a suitable test of statistical significance on appropriately collected data
- 4) Compare the p value from the test with the alpha level
- 5) Fail to reject the null hypothesis
What are the six steps to the scientific method?
- 1) Observe an event
- 2) Develop a model (hypothesis) that makes a prediction
- 3) Test the prediction
- 4) Compare the p value from the test with the alpha level
- 5) Reject or fail to reject the null hypothesis
- 6) Repeat as needed
What is biostatistics?
A science that deals with the collection, organization, analysis, interpretation and presentation of information that can be stated numerically with regard to medical, public health and biological applications
What are the 4 main activities of an epidemiologist?
- 1) Design Studies
- 2) Collect and organize data,
- 3)summarize results using appropriate statistical tests
- 4) critically interpret findings
To be a responsible epidemiologist you should know to not rely on ________ with a statistican
To be a responsible epidemiologist you should know how to distinguish between _________ data and routine __________
A statistic is..
an estimate based on a sample of an unknown numerical quantity in the population
If information is based on a ______ of the population, we want to use this information to make inductive inferences about the _________
When data is collected from a sample of a population, what should you do with the data?
make inferences about the underlying population
What's the main "equation" of biostatistics?
(Good sample data representative of the population) + (Good application of satistical methods) = (Good estimates of relevant parameters) + (Good decisions about whether or not certain hypotheses are tenable)
What are the five things (issues) an epidemiologist must do?
- 1) Have to clearly define the research question
- 2) Must choose the most appropriate study design
- 3) Must select a representative sample for study
- 4) Must collect data appropriately
- 5) Must summarize using appropriate statistical methods in order to make the correct inferences
If a study was incorrectly planned or executed, no amount of statistical expertise can _______ the results
What are the 4 main statistical needs in the early stages of research?
- 1) Recommend study designs for a given research question
- 2) estimate the number of subjects (sample size) needed to achieve study objectives
- 3) Develop efficient data collection methods
- 4) Recommend ways to monitor the quality of data as it is collected
What are the three statistical needs after the data is collected?
- 1) Recommend most appropriate statistical methods for analysis
- 2) Interpret the findings in understandable terms
- 3) Review and contribute to presentations and publications
Why do we need EEh 505?
Because you should have a good understandingstatistics to aid all future collaborations
The higher the "impact factor" of a publication the _______ it is
The impact facotr reflects what?
The number of times articles are cited
The impact factor is not necessarily an indicator of _________
What are the three ways research is judged?
- 1) It's perceived "impact factor"
- 2) Subsequent frequency of citation in new peer-reviewed research
- 3) Reports of consistent (or inconsistent) findings [whether the results can be replicated or not]
"Inference" is another word for..
Our goal is to make the strongest possible ________ from limited amounts of _____
conclusions (inferences) data
What do frequency distribution list?
Each value in the data and the frequency with which it occurs
Descriptive statistics are used to..
Summarize the information in a collection of data
Inferential statistics are used to..
Provide predictions about a population, based on a sample of the population
What are the four things a good scientific study includes?
- 1) Clearly stated objectives
- 2) Clearly stated hypothesis
- 3) Specific effect to be estimated
- 4) Specify defintions of terms essential to the study
The inferences we wish to make are limited by what two things?
Study design and selection of subjects.
What do we use study units for?
To make inferences about the population
Study units make up the _________
Increasing the number of measurements taken on a study unit is not the ________ to increasing the number of study units.
The population is...
the total set of subjects of interest in a study
The sample is...
the subset of the population on which the study collects data
What do we call the quantity computed from the sample data?
What is a parameter?
A quantity that is characteristic of the population
If a sample is representative of the population, _____________ will give accurate impressions of the corresponding __________ of the population
descriptive statistics parameters
What is a target population?
The whole group of study units to what we are interested in applying our conclusions
Target population is also known as..
What is the study population?
The group of study units to which we can legitimately apply our conclusions
The study population and the inaccessible study units together make up..
The accessible study units solely make up the..
What are the two main types of epidemiologic studies?
Observational and Experimental
Observational studies are where the researcher..
observes the study units, makes measurements and make inferences that are limited to descriptions and associations
Experimental studies are where the researcher..
intervenes (experiments) in some way to affect the manner in which the study units(experimental units) respond
In a _____ study, you follow exposed and non-exposed individuals over time
In a ______ study, you identify a sample of individuals with the disease and without