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What |is |biostatistics? |- |correct |answer |✔Discipline |concerned |with |the |treatment |and |analysis |of |numerical |data |derived |from |biological, |biomedical, |and |health-related |studies.
What |is |measurement? |- |correct |answer |✔How |we |get |our |data... |the |assignment |of |numbers |of |codes |according |to |prior |set-rules
What |are |the |three |disciplines |of |biostatistics? |- |correct |answer |✔1. |Improve |intellectual |content |of |data.
- |Organize |data |into |a |format |that |is |understandable.
- |Relies |on |tests |of |experience |as |standard |of |validity.
What |is |an |observation? |example? |- |correct |answer |✔The |unit |upon |which |a |measurement |is |made. |ex: |a |person |or |a |region.
What |is |a |variable? |- |correct |answer |✔A |characteristic |being |measured.
What |is |a |value? |- |correct |answer |✔A |number |or |code |that |has |been |realized
How |do |you |set |up |a |data |table? |- |correct |answer |✔Observations |in |rows
Variables |in |columns |
Values |in |the |middle
When |would |you |use |a |categorical |scale? |Example? |- |correct |answer |✔When |there |are |two |or |more |categories |with |no |intrinsic |ordering |to |the |categories. |Example |- |gender, |blood |type, |disease |state.
When |would |you |use |an |ordinal |scale? |Example? |- |correct |answer |✔it |puts |observations |into |categories |that |can |be |ranked/ordered. |Ex: |cancer |stages.
When |would |you |use |a |quantitative |scale? |Example? |- |correct |answer |✔For |numeric |values. |Ex: |height, |weight, |age.
What |is |objectivity? |- |correct |answer |✔The |intent |to |measure |things |as |they |are |without |shaping |them |to |conform |to |a |preconceived |worldview.
What |are |the |two |forms |of |measurement |errors? |- |correct |answer |✔1. |Imprecision |
- |Bias
What |is |imprecision? |- |correct |answer |✔The |Inability |to |get |the |same |result |on |repeat.
What |is |reliability? |- |correct |answer |✔Ability |to |replicate.
What |is |bias? |- |correct |answer |✔The |tendency |to |overestimate |or |underestimate |the |true |value.
Ex |- |divide |the |population |into | 5 |year |age |groups |and |SRS |within |that
What |is |a |cluster |sample? |- |correct |answer |✔Randomly |selects |large |units |with |smaller |subunits.
What |is |probability? |- |correct |answer |✔The |proportion |of |times |an |event |is |expected |to |occur |in |the |population |- |useful |for |predicting |future |outcomes.
What |is |the |explanatory |variable? |- |correct |answer |✔The |treatment |or |exposure |that |explains |or |predicts |changes |in |the |response |variable.
What |is |the |response |variable? |- |correct |answer |✔The |outcome |or |response |being |investigated
What |is |confounding? |- |correct |answer |✔A |distortion |in |an |association |between |an |explanatory |variable |and |response |variable |brought |about |by |the |influence |of |extraneous |factors.
What |is |an |interaction? |- |correct |answer |✔Factors |in |combination |produce |an |effect |that |could |not |be |predicted |by |looking |at |the |effect |of |each |factor |separately.
What |is |blinding? |What |are |the |types? |- |correct |answer |✔Technique |where |individuals |in |the |study |are |kept |unaware |of |the |treatment |assignments |
Single |- |subject |unaware
Double |- |subject |and |investigator |unaware
Triple |- |subject, |investigator, |and |statistician |unaware
What |is |equipoise? |- |correct |answer |✔The |balance |of |doubt |versus |benefits |and |risks |for |a |study.
What |do |you |have |to |make |sure |to |add |at |the |bottom |of |your |stem |and |leaf
|plot? |- |correct |answer |✔The |axis |multiplier
What |are |the |types |of |kurtosis? |- |correct |answer |✔Platykuric |= |flat |with |broad |tails |
Leptokuritic |= |tall |with |skinny |tails |
Mesokurtic |= |medium
What |are |the |types |of |skew? |- |correct |answer |✔Positive |skew |= |more |toward |larger |numbers |(to |the |left) |
Negative |skew |= |more |toward |smaller |numbers |(to |the |right)
What |is |spread? |- |correct |answer |✔The |dispersion |or |variability |of |data |points.
How |do |you |calculate |relative |frequency? |- |correct |answer |✔The |frequency |count |divided |by |the |total |count.
What |is |the |difference |between |a |bar |chart |and |a |histogram? |- |correct |answer
|✔Histograms |the |bars |are |touching
How |do |you |draw |a |box |and |whisker |plot? |- |correct |answer |✔
What |are |considered |outliers |when |drawing |a |box |and |whisker |plot? |- |correct |answer |✔Data |outside |the |upper |and |lower |fences:
Lower |= |Q1 |- |(1.5)(IQR)
Upper |= |Q3 |+ |(1.5)(IQR)
What |are |the |most |common |measures |of |spread? |- |correct |answer |✔Variance |and |standard |deviation.
How |do |you |calculate |the |standard |deviation? |- |correct |answer |✔1. |Determine |deviation: |X1 |- |Xbar
- |Square |the |deviation: |(X1-Xbar)^
- |Sum |the |squared |(SS) |
- |Divide |the |SS |by |(n-1) |to |get |variance |(s2) |
- |Take |the |square |root |of |the |variance
What |is |the |equation |for |standard |deviation? |- |correct |answer |✔
What |is |s? |- |correct |answer |✔Standard |deviation
What |is |SS? |- |correct |answer |✔The |sum |of |squares
What |is |s2? |- |correct |answer |✔The |variance
What |do |the |deviations |of |a |data |set |always |sum |to? |- |correct |answer |✔ 0
What |is |the |confidence |interval? |- |correct |answer |✔The |range |of |values |in |which |the |true |result |probably |falls.
How |do |you |calculate |degrees |of |freedom? |- |correct |answer |✔n-
What |is |Chebychev's |rule |regarding |standard |deviation? |- |correct |answer |✔In |all |data |sets, |at |least |3/4ths |of |the |points |will |lie |within | 2 |standard |deviations |of |the |mean
What |is |the |normal |rule |for |standard |deviations? |- |correct |answer |✔In |data |sets |with |normal |distributions |- |68% |of |points |will |be |within |one |standard |deviation, |95% |of |points |will |be |within |two |standard |deviations, |and |99.7% |of |points |will |be |within |three |standard |deviations.
How |does |the |standard |deviation |compare |to |the |IQR? |- |correct |answer |✔Standard |deviation |is |more |efficient |measure |of |spread |by |it |is |less |robust... |preferred |when |the |distribution |is |symmetrical.
What |is |the |sum |of |all |possible |probabilities |for |a |sample |space? |- |correct
|answer |✔ 1
What |is | μ? |- |correct |answer |✔Population |mean
What |is |a |discrete |variable? |- |correct |answer |✔It |has |a |countable |set |of |possible |outcomes.
What |is |a |continuous |variable? |- |correct |answer |✔It |has |an |unbroken |continuum |of |possible |outcomes |(like |average |weight |of |newborns |w/ |SIDS)
What |is |a |statistical |inference? |- |correct |answer |✔The |act |of |using |data |in |a |particular |sample |to |make |generalizations |about |the |population |in |which |it |came |from
What |is |a |parameter? |- |correct |answer |✔A |numerical |characteristic |of |a |statistical |population
Where |do |parameters |versus |statistics |come |from? |- |correct |answer |✔Parameters |- |population |
Statistics |- |sample
What |is |the |sampling |distribution |of |the |mean? |- |correct |answer |✔Hypothetical |distribution |of |means |from |all |possible |samples |of |size |n |taken |from |the |same |population.
What |is |the |law |of |large |numbers? |- |correct |answer |✔As |an |SRS |gets |larger |and |larger, |the |sample |mean |is |likely |to |get |closer |to |the |true |value |of |the |population |mean.
What |is |a |statistical |population? |- |correct |answer |✔The |entire |collection |of |values |about |which |we |want |to |draw |conclusions.
What |is |the |power |of |a |study? |- |correct |answer |✔The |probability |of |finding |and |affect... |probably |of |rejecting |the |Null.
What |is |the |central |limit |theorem? |- |correct |answer |✔Given |a |sufficiently |large |sample |size |from |a |population |with |a |finite |level |of |variance, |the |mean |of |all |samples |from |the |same |population |will |be |approximately |equal |to |the |mean |of |the |population.... |so |Xbar |tends |towards |normality |even |when |the |population |distribution |is |not |normal.
How |do |you |calculate |the |z |score? |- |correct |answer |✔Convert |it |into |the |p |value |with |a |table
What |do |you |do |to |the |p |score |for |two-tailed |hypotheses? |- |correct |answer |✔Multiply |it |by | 2
When |can |we |use |a |z |score? |- |correct |answer |✔When |the |population |is |normal |
When |it |is |mound |shaped |and |symmetrical |for |samples |> | 10 |
When |it |is |prominently |skewed |for |samples |> | 40
What |is |a |Type | 1 |error? |- |correct |answer |✔Rejection |of |a |true |null |hypothesis. |(alpha)
What |is |a |Type | 2 |error? |- |correct |answer |✔Retention |of |a |false |null |hypothesis. |(beta)
Ha: |at |least |one |of |the | μis |differ
What |statistic |chart |do |we |look |up |in |the |back |of |the |book |for |ANOVA? |- |correct |answer |✔F |stat
What |is |"Mean |Square |Between" |? |What |does |it |pertain |to? |- |correct |answer
|✔ANOVA |is |based |on |this |principal |- |variability |of |group |means |around |the |grand |mean |provides |a |signal |of |group |difference
What |is |the |notation |for |ANOVA? |- |correct |answer |✔SSB ≡ |sum |of |squares |between
dfB≡ |degrees |of |freedom |between
k≡ |number |of |groups
x-bar | ≡ |grand |mean
x- bari≡ |mean |of |group
What |do |you |pursue |after |rejecting |ANOVA |null |hypothesis |to |delineate |differences |in |groups? |- |correct |answer |✔Post |hoc |comparisons
What |are |the |three |assumptions |for |ANOVA? |- |correct |answer |✔1. |Sapling |independence
- |Normal |sampling |distribution |of |mean
- |Equal |variance |within |population |groups
What |is |homoscedasticity? |What |does |it |allow |us |to |do? |- |correct |answer |✔Equal |variance |
Allows |us |to |pool |group |variances |to |form |the |MSW
How |do |you |assess |equal |variance |so |you |can |use |ANOVA? |(3 |ways) |- |correct
|answer |✔1. |graphical |exploration |
- |Descriptive |stats
- |Test |variance |(Levene's)
In |what |ways |can |you |manipulate |the |data |to |analyze |groups |with |unequal |variance? |- |correct |answer |✔Stay |descriptive
Remove |out-liars |
Use |non-parametric |methods |
Mathematically |transform |the |data
Match |the |test |with |the |nonparametric |test? |- |correct |answer |✔One |sample |t |--
|Wilcoxon |
Paired |t |--> |Paired |wilcoxon |
Independent |t |--> |Mann |- |whitney |
ANOVA |--> |Lruskal-Wallis |
Pearson's |correlation |--> |Spearman's |rank
What |hypotheses |are |you |testing |when |running |a |chi-square? |- |correct |answer
|✔H0: |no |association |in |population |versus |
Ha: |association |in |population
When |do |you |have |to |avoid |using |chi |square? |- |correct |answer |✔In |small |samples
What |do |you |have |to |supplement |chi-square |with? |- |correct |answer |✔Measures |of |association |to |quantify |the |strength
What |is |an |odds |ratio? |- |correct |answer |✔The |odds |of |an |event |= |proportion |of |successes |divided |by |the |proportion |of |failures
What |are |the |characteristics |of |chi |square |distributions? |- |correct |answer |✔Start |at | 0
Asymmetrical |
More |symmetrical |as |DF |increases |
Mean |equal |to |df |
Variance |equal |to |2xdf
