# Shared Flashcard Set

biostats
test 1
104
Nursing
06/04/2012

## Additional Nursing Flashcards

Term
 a set of inter-related constructs (concepts), definitions, propositions, that present a systematic view of phenomena by specifying relations among variables for the purposes of explaining and predicting phenomena
Definition
 theory
Term
 the ____ tests the theory
Definition
 hypothesis
Term
 this is the statement of the relationship between the independent and the dependant variables
Definition
 hypothesis
Term
 this is the investigator's hunch or expectation
Definition
 research hypothesis
Term
 another name for a guiding hypothesis
Definition
 research hypothesis
Term
 what is the  statement that allows verification by using a test?
Definition
 statistical hypothesis
Term
 null hypothesis (ho)
Definition
 "there will be no statistically significant difference"
Term
 the null hypothesis is based on the _____ of _____
Definition
 laws of proof
Term
 what is the laws of proof?
Definition
 if one can falsify the null then the opposite or alternative must be accepted
Term
 define directional hypothesis (hd)
Definition
 there will be a statistically significant difference in indicates where the difference will be found(ie the direction) * not commonly used in research, except in epidemiology b/c assumed exposure to diseases or agents usually doesn't result in better health!
Term
 this variable is the characteristic that the researcher controls or manipulates according to the purpose of the study   used to classify or categorize subjects or groups
Definition
 independent variable
Term
 a measure of the effect of the independent variable used to measure outcomes or compare differences may be measured before and after the conditions are manipulated
Definition
 dependent variable
Term
 these are variables that interfere in a study "bugs", must be eliminated(controlled) characteristics not of primary interest that affect the dependent variable
Definition
 intervening (confounding) variables
Term
 name the four levels of measurement
Definition
 Nominal ordinal ratio interval
Term
 examples of nominal levels of measurement and definition
Definition
 mutually exclusive categories, but have no order or meaning   male, female,   No mathmatics**
Term
 define ordinal levels of measurements
Definition
 mutually exclusive categories based on some defined characteristics and the relative amt of that characteristic with a logical order to the categories ex agree, disagree,   never use math on this level of data**
Term
 which levels of data do you not use math on?
Definition
 NO math on   Nominal Ordinal
Term
 discuss interval data
Definition
 classifies objects into mutually exclusive categories based on defined characteristics logical order and equal units of differences   example= units   can use math
Term
 ratio levels of measurement
Definition
 mutually exclusive categories, based on some defined characteristic  and the relative amt. of that characteristic with a logical order, equal units of difference and a meaningful zero point, representing absence of the characteristic example= # of cigarettes WBC count
Term
 2 types of categorical data
Definition
 nominal and ordinal
Term
 2 types of continuous measures
Definition
 ratio and interval
Term
 formula for observed measurement=
Definition
 observed measurement= the true value + error
Term
 can you use means, standard deviations for ordinal level data?
Definition
 No
Term
 are small or large sample sizes vulnerable?
Definition
 small are more vulnerable
Term
 chance variation is also called what?
Definition
 error
Term
 _____focuses on the consistency with which a measurement is taken?
Definition
 Reliability
Term
 discuss instrument reliability
Definition
 focuses on the consistency of measurement by a particular instrument- what if the instrument is faulty? the key with instrument reliability is calibration
Term
 intra-rater reliability focuses on what?
Definition
 consistency with which an individual takes measurements is it done the same by the person every time? poor technique? consistenly following technique?
Term
 inter-rater reliability focus on what?
Definition
 consistency in measurements between or among more than 1 individuals taking the measurements. must be an adequate assurances that changes are true rather than b/c of error- *does everyone follow the same protocol for measuring?
Term
 is the pearson correlation appropriate for measuring reliability? why or why not?
Definition
 No, b/c it ignores systematic errors
Term
 wwhat is the preferred measure for reliability for continuous data?
Definition
 ICC-itra-class correlation coefficient
Term
 the best ways to improve reliability are to do what?
Definition
 follow a protocola and practice the protocol before taking measurements
Term
 ICC ranges
Definition
 0 to 1.00 0.9 or above -excellen reliability .75-0.89 good to verygood below 0.75 mod to poor the lower the worse
Term
 reasons for low ICC
Definition
 1. rateres and ratings do not agree 2. lack of sufficient variability of subjects' scores(range)
Term
 what does measuring validity mean?
Definition
 does the test or measure actually do what it is intended to do? are we measuring what we think we are measuring?
Term
 what type of validity? does the mesurement appear appropriate?
Definition
 face validity
Term
 what type of validity is the measurement based on theory?
Definition
 construct validity?
Term
 waht type of validity   is the test broad enough to address the scope of the content? (example: anatomy, only covers sm. part of the body, not the whole thing)
Definition
 content validity
Term
 what type of validity?   how does the test perform? is it useful?
Definition
 criterion validity
Term
 what type of validity   does the test predict a specific phenomenon or outcome?
Definition
 predictive validity
Term
 what type of validity?   does the test perform as well as an accepted test? does a smaller test do as good as a bigger, or the gold standard?
Definition
 concurrent validity
Term
 what type of validity? does the test predict well enough to determine an intervention?
Definition
 prescriptive validity
Term
 what type of validity is concerned with limiting or controlling factors and events, other than the independent variable, which may cause changes in the outcome(dependent variable)
Definition
 internal variable
Term
 which type of validity is concerned with factors which may affect the generalization of the conclusions drawn from a study
Definition
 external validity
Term
 what are the three temporal threats to internal validity?
Definition
 history, maturation, and attrition history-passage of time, maturation-age(developmental changes, like that of a toddler) attrition-drop out, ex. if happy with treatment drop out of study, the only ones left are those who are not being helped
Term
 what are the threats to measuring effects on internal validity
Definition
 testing-the act of testing itself, once testing is done learning is done about test, can't repeat instrumentation- what if there is a problem with instrument chosen to test (ex in class testing writing with "pencil-like object" but not really pencil, this learning affects handwriting also) statistical regression to the mean-tendancy for outliers to move toward the mean as test is repeated, due to laws of probability sampling-bias
Term
 population effects to external variability
Definition
 1. accessibility-the subject may not represent the entire population, which may include individuals wha have comprimised access to medical care and treatment 2.  subject treatment interaction-everybody reacts differently-we are all genetically different.
Term
 ecological threats and concerns related to external validity
Definition
 1. description of the variables-not given enough data to exactly replicate and get same results 2.  multiple treatments (test order)-potentiation of therapies-fatigue, physiology of test-what was done first
Term
 this is an effect on test subjects knowing they are test subjects, they have better compliance than those not be tested-it is a threat to external validity
Definition
 hawthorne effect
Term
 discuss pre-test/post-test sensitization
Definition
 individuals anticipate what will be tested, this is an external validity threat
Term
 what is it called when a person's charissma or the person doing the study affects the outcome ?
Definition
 Rosenthal effect-example of a threat to external validity
Term
 R= M= O= X=
Definition
 R=randomized M=subjects are matched O= means measurement X=treatment
Term
 what type of design is characterized by no control group sesitivity to temporal threats to internal validity poor generalization
Definition
 pre-experimental designs
Term
 the investigator measures temp. of a sample of children on day before and one day after innoculation   plot and this is an example of what?
Definition
 O   X   O    pre-experimental design "before-after" no control grom is described
Term
 what type of design is the gold standard randomized-likelihood is balanced there is a control group-comparison
Definition
 experimental designs
Term
 randomization is used to help _____ factors among groups
Definition
 balance
Term
 randomization means what?   not?
Definition
 randomization= equivilant NOT=identical
Term
 ex. women with RA were randomly assigned to one of 3 tx groups: heat, cold, contrast baths, edema was measured using an immersion technique one day before tx and later after they received 6 tx's (before tx and after tx measurements)   plot and describe design
Definition
 this is a pretest-post test control group design using 3 groups. because pts are used a strict control (withholding tx) cannot be used R  O X1 O R  O X2 O R  O X3 O
Term
 ex. in order to compare the effects of tPA and no tPA , pts presenting within 4 hrs of a CVA were randomly selected to receiveor not receive tPA. 6 days after admission to hosp. pts. wree compared   do diagram and explain this test
Definition
 R  XtPA  O R XnotPA O   tis is experimental design, but no pretest is possible b/c cannot prediagnose CVA
Term
 do diagram and explain type of test in order to test the effect of pos. imagery on psycomotor skills 2 classes form the same school were used.  the subjects in 1 class received instruction on visual imagery  while the other class did not.  Subjects' times to complete the psycomotor test battery were measured before and after one clase received visual imagery training
Definition
 this is a quasi-experiment b/c 2 whole classes were compared and one does not know it is the equivalent   O  X1  O ----------- O X2  O
Term
 this type of design has characteristics of experimental design, but lacks at least 1 of the typical characteristics that would make them"true" experimental design.
Definition
 quasi-experimental design
Term
 all members defined on some specification
Definition
 population
Term
 a  subset of a population is a _____
Definition
 sample
Term
 a descriptor ex. avg age
Definition
 parameter
Term
 what type of sample?   any subject that qualifies is included
Definition
 convenience
Term
 what type of sample?   all potentioal subjects from a specific source
Definition
 cluster
Term
 all subjects are chosen form a protocol, for example, every fifth M and M is what type of sample?
Definition
 systematic
Term
 this type of sample -subjects are chosen so that the composition lof the sample represents the population on specified characteristics (ex. if asking nurses and 85% are female-make sure 85% of your sample is also female) want it to look similar
Definition
 stratified
Term
 type of sampling-every potential subject has an equal likelihood of being included in the sample
Definition
 random sampling
Term
 black jack is what type of sampling?
Definition
 random without replacement
Term
 what type of sampling-after a subject is chosen at random, the subject is returned to the population, usually not used in clinical research odds don't change-slot machine! 50 in 1 is same as 1 in 50
Definition
 random sampling with replacement
Term
 what type of sampling- after a subject is chose at random the subject is not returned to the population this method is typically used in clinical researc
Definition
 random sampling without replacement
Term
 what is the probability?
Definition
 it's the proportion of outcomes that meet a criterion divided into all possible outcomes
Term
 probability of having a girl
Definition
 p= girl/boy, girl 1/2=50%
Term
 replacement vs not drawing the king of hearts in 2 draws replacement 1/52 AND 1/52 no replacement 1/52 and 1/51
Definition
Term
 what is the measures of central tendency?
Definition
 describes the population sample(descriptive statistics) useful as a shorthand describes the most typical subject
Term
 examples of measures of central tendancy
Definition
 mean, median, and mode
Term
 what measure of central tendancy is the only one that can be used for nominal data?
Definition
 Mode-b/c it is just stating what the most common score is
Term
 what is the mode?
Definition
 the most common score all levels of measurement may be more than 1 mode
Term
 what is median?
Definition
 the value occuring at the midpoint when the data is arranged in order of magnitude useful for skewed distributions ordinal, interval or ratio data
Term
 what is the mean?
Definition
 the sum of the scores divided by the number of subjects (mathematical average) interval or ratio level data
Term
 parameters describe _____   statistics describes_____
Definition
 parameters- populations statistics -samples
Term
 use ____ in the denominator in the equation for calculating sd because using __ underestimates the dispersion for small sample sizes
Definition
 use n-1, not n
Term
 greek letters are used to denote_____ latin letters are used to denote_____
Definition
 greek-paramenters latin-statistics
Term
 what is the preferred measure of central tendancy for skewed distribution?
Definition
 median
Term
 µ
Definition
 population mean
Term
 σ
Definition
 the population standard deviation
Term
 __ X
Definition
 sample mean
Term
 s or sd
Definition
 standard deviation
Term
 positive skew is to the
Definition
 skewed to the right
Term
 negative skew is skewed to the ___
Definition
 left
Term
 formula for range
Definition
 max-min
Term
 formula for variance
Definition
 s2
Term
 if the sample is trimmed what does this mean?
Definition
 outlying scores are dropped
Term
 if original distribution is trimmed by 10% what does this mean?
Definition
 5% trimmed on each side of curve
Term
 if a mean is winsorized what does this mean?
Definition
 20% on each side dropped and replaced by the remaining highest and lowest number, this will often make the mean lower than the median
Term
 in a bar chart how is data seperated?
Definition
 each bar or segment represents one category and is seperated from the others
Term
 bar charts are useful for ____ and _____ data
Definition
 nominal and ordinal
Term
 in a histogram what do the segments represent?
Definition
 the bars or segments touch and represent ranges rather than single values-intervals
Term
 histograms are useful for what type of data?
Definition
 interval and ratio level data
Term
 a skewness of <___ is ok
Definition
 <2
Term
 kurtosis
Definition
 flattened part of the peak
Term
 in normal distribution -1 to +1 is____% -2 to +2 is____% -3to +3 is ____%
Definition
 65% 95+% >99%
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