Health Sciences Flashcards
What are the 5 steps to understand The Scientific Method?
- Observation/Theory
- Generate Hypothesis
- Gather Data
- Analysis Data
- Draw Conclusions
Define the scientific method?
The Scientific Method involves repeating generating and testing theories and hypothesis
What us inferential uncertainty
Wether the pattern we find in data in something we would find normally or if it actully means something
What is a z-score
What is the calculation for a z-score of a group
Z-scores represent how far that value is from the population mean in standard deviation units
Z-score for group- X - u
o / N
What does which of these symbols mean
Z-score=
X
u
o
X = score
u = population
o = population standard deviation
What is a confidence interval
An estimated range of variables for a population parameter
An average of 9 weeks (point estimate) or between 7-9 weeks (confidence interval)
What are effect sizes
n2, Cohen’s d, r2
Measure of the size of an effect that ignores the sample size –> a measure of practical significance
Is it ACTULLY important
Cohen’s d = M1-M2
6
Difference between population means ÷ standard deviation
Effect Sizes
Small effect = ______
Medium effect = ______
Large effect = ______
Small = 20
Medium = 50
Large = 80
What is the equation for varience
Average distance of each response from the average response
= E ( x-x )2
N-1
What is a Quasi Experiment
When you can’t manipulate the IV and just measure the DV
What is a Quasi Experience
When you can’t manipulate the IV and just measure the DV
The value of r is always between
_____ and _____
-1 and 1
R2 is always 0-1 because squared numbers are always +
What are the strength of relationship for
Weak 0.00 -> _____
Moderate _____ -> .49
Strong 50 -> ______
Weak 0.00 -> .29
Moderate 0.30 -> 0.49
Strong 0.50 -> 1.00
Interpreter the correlation
1. r(498) = .62, p .047
2. r(500) = .36, p .063
3. r(367) = .48, p .024
- Strong positive correlation, significant
- Moderate negative correlation, not significant
- Moderate negative, significant
Why would we do a one sample t-test
What are the degrees of freedom
When you don’t know what the standard deviation of the general population
Between-Subject-Desig
Df = N-1
a) what is an IV
b) what is a DV
a) independent variable: variable manipulated by the experimenter
- can be more then one
- in some cases can be measured
b) dependant variable: measured observing how the IV influences the DV
What is Pearson’s r
- correlation coefficient - measuring the relationships between variables
- r2 is the amount of shared variance between the tested variables
What is a two-tailed test
What is a one-tailed test
Two-tailed - non-directional, rejection regions on both sides
One-tailed - directional, only care about one side
What is a type I error
What is a type II error
Type I error: When you incorrectly reject the Ho
Alpha (a) probability of type I
Type II error: when you incorrectly accept the Ho
Beta (b) probability of type II
What are odds ratios
Written as OR
Relative measure of effect - compare an intervention group to a control group
Represents the odds that an outcome will occur given a particular exposure, compared to the odd of the outcome occurring in the absence of that exposure
What is
- Content Analysis
- IPA
- Narrative Analysis
- Discourse Analysis
- Thematic Analysis
- Analysis of content (what is being said)
- Interpretation phenomenological Analysis (IPA) (how people identify meaning)
- Examine people’s use of stories
- Analysis written, spoken, or signed language (about how its being said)
- Summarise key ideas - comparrison
What are the ethical principles of research
-Autonomy (voluntary participation? Capacity discontinuation)
- Beneficence and non-maliticence (Benefits,Harm?)
- Informed concent (required, deception, debrief)
- Confidentiality (identifiable, data storage)
- Justice (social impacts)
- Integrity (conflict of interest, Intellectual property?)
What is the standard error of the mean
What’s is the formula
Standard error of the mean is the standard deviation divided by the square root of the sample size
6
N
What is a within - subjects t - test vs between subjects t - test
The same subjects are used/exposed to the IV at different times
Mean = difference score (D)
The experimental manipulation occurs between the control group and experimental groups
What are inferential statistics
What is a p value
Making predictions about a population based on a sample takes from the population
P value = probability
What do these symbols mean
- X
- D
- SD
- u
- N
- B
- a
- 6
- S2 pooled
- Mean of the population or sample
- Mean difference
- Standard deviation
- Population mean
- Total number of participants
- Beta
- Alpha
- Standard deviation
- Pooled variance -> average of two variences
What are the assumptions of t-tests
Assumptions of Independence
Assumptions of Normality - nominaly distributed
Assumptions of Equal Varience
When to use correlation
When you want to quantify a linear relationship between to variables
Neither of the variables are a response or outcome variable
What is a positive correlation
What is a negative correlation
Positive- the higher one score is, the higher then other
Negative- as one value increases the other decreases
What is the mean, medium, mode
What’s the equation for the mean and standard deviation
Mean - average response
Median - the response of the average person
Mode - most common response
Mean = E X
N
SD = share root E (X - X) 2
N - 1
What is power and its components
- probability of correctly rejecting the null hypothesis (H0)
- power = I - B
- beta is the likelihood of type II error
- higher alpha increases power (a)
- sample sizes increasing N increases power
- sample variance smaller means more power
What is the difference between parametric and non-parametric tests
- parametric depends on certain assumptions (interval or ratio data)
- non-parametric tests are used when you don’t have the appropriate data
Aren’t confident to make assumptions, data isn’t normally distributed, distribution free tests
What is validity
a) construct validity
b) external validity
Name common threats
a) asking if it measures what it’s suppose to
b) can it be applied to the general population (generalise)
Sampling bias, mortality, reactivity, observer effect, internal validity, testing effects, history effects, ecological validity.
What is the scientific method
Draw a flow chart
The process by which scientists collectively and over time, endevor to collect an accurate representation of the world.
- Observation
- Question
- Hypothesis
- Experiment
- Conclusion
- Result
Give an example of the following
- research hypothesis
- null hypothesis (H0)
- alternative hypothesis (H1)
What we think is going to happen
Hypothesis that states nothing will happen H0
Hypothesis that states there will be a change H1
What are examples of non-parametric tests
- Chi-square goodness of fit
- Chi-square test of independence
- Mann - Whitney U-Test
- Wilcoxons signed ranks test
- Krushal - Walt’s test
What is the chi-square formula
Pronounced kai-square
Comparing observed frequencies with expected frequencies
X2 = E (0-E)2
E
0 = observed/ obtained data
E = expected frequencies
What is Alpha
Alpha or a is the cut off
If p value is smaller then Alpha then we reject the null hypothesis
Usually 0.05.
What are 4 types of research data
- Nominal measures: response are categorised or classes (gender)
- Ordinal measures: are ordered on a continuum but intervals are not always equal (1st, 2nd, 3rd)
- Intervals measures: quantively related, equal Intervals with no true zero ( personality scale)
- Ratio measures: similar to Interval but has a true zero (height,weight,age)
