Lecture 1 Flashcards
Define Statistics
Technique where data’s organized, treated, & presented for interpretation
Reasons Why Statistics are Useful?
1.) Calculating probabilities
2.) Comparing things from same group
3.) Determine how treatment affects outcomes
4.) Likelihood of making a wrong conclusion (type 1 error)
5.) determine strength of conclusion-supporting evidence
How are Statistics used?
4 ways
1.) to determine best treatments
2.) to make clinical diagnoses
3.) to form tests & theories
4.) to make evidence-based decisions
What is Measurement?
Process of comparing a value to a standard
What are 4 types of Measurements used in stats?
1.) Distance - eg; height, long jump distance
2.) Force - eg; body weight, isometric strength
3.) Time - eg; # of seconds to complete 100m race
4.) Frequency - eg; heart rate in beats per minute
2 things that make a good measurement?
1.) Reliability
2.) Validity
What is Reliability?
Reproducibility & consistency
What is Validity?
- provide an example
Test measures what it is designed to measure
- often a correlation from 1 test to another
- eg; 6-min walk test for VO2Max estimation
What are Variables?
Characteristics of a person, place, or object that can assume more than one value
- includes; anthropometric & performance outcomes
What are Constants?
Characteristics that do not change
- eg; competition distances, weight categories…
What are the 3 types of Measurement Scales we will be using?
1.) Ordinal
2.) Interval
3.) Ratio
What is the Ordinal Measurement Scale?
- defining characteristic & example
scale ranks participants/objects
- Eg; rankings in sport (doesn’t tell you how much someone is better by)
What is the Interval Measurement Scale?
- defining characteristic & example
Equal units of measurement with no true 0 (eg; 0 degrees C doesn’t mean there is no temperature)
- eg; temperature
What is the Ratio Measurement Scale?
- defining characteristic & example
Scale has an absolute 0 (0=absence of value)
- eg’ weight, distance, marks on exams, etc.
What is a Theory?
A belief regarding a concept or series of related concepts
- generate hypotheses to be tested
- eg; gravity, evolution, sliding filament theories
- theories derive from hypotheses that survive testing
What is a hypothesis?
Something that must be testable & falsifiable
- not 100% correct 100% of the time
What is a Null Hypothesis?
H0 = a hypothesis opposite to the real hypothesis
It is the hypothesis you are trying to reject
What are 3 different types of research design?
1.) Historical
2.) Observational
3.) Experimental (associated with science)
Hypothesis Testing - 2 ways this can be done
Hypothesis testing uses a research/alternative hypothesis and a null hypothesis
- can be directional or non-directional
Directional vs Non-Directional Hypothesis Testing
In directional tests you hope to see a change in a specific direction (preference on what the outcome is)
In Non-Directional tests something will happen but unsure of what (+’ve or —‘ve)
Review Hypothesis percentiles slides**
What are Independant Variables?
- 3 examples
Variable that can be changed or adjusted
- eg; height, exercise program, & type of lacrosse stick
What are Dependent Variables?
- 3 examples
Variables that you measure & cant be changed
- eg; points per game, 1RM max, throwing accuracy
How are dependent and independent variables related?
Independent variables determine the outcome of dependent variables
- as practice increases (IV)… skill increases (DV)
What is Internal Validity?
Control in experiment to make sure results are due to treatment
- assessment of quality of experimental control
- common techniques = control/placebo conditions, randomization, & blinding
When discussing Internal Validity, what are Intervening (extraneous) Variables?
Fatigue or learning effects from repeated testing
When discussing Internal Validity, what is Instrument Error?
Poor calibration or loss of calibration
When discussing Internal Validity, what is Investigator Error?
Error in skinfold technique, data entry errors, etc
What is External Validity?
Ability to generalize results of an expirament to the population from which the samples were drawn
What are a couple questions to consider when discussing external validity?
1.) How well does the sample reflect the population of interest?
2.) Are sample results from college athletes generalizable to professional athletes?
**tight experimental control may make study unrealistic in real world
Define Population
Any group of persons, places, or objects that have atleast one common characteristic
What is a Sample?
A subset of a population
- you need samples that are representative of the population of interest
- random sample = each member of population has = opportunity of being selected into the sample
What is Bias in a Sample?
extraneous factors operate on the sample to make it unrepresentative of the population
What is a Parameter?
A characteristic of the population
Define Statistics
A characteristic of a sample that is used to estimate the value of the population parameter
