Week 7 - Quant Research Design & Descriptive Stats Part 2 Flashcards
define descriptive statistics
- Describe and synthesize data
- Summarize sample characteristics
- Describe key research variables
- Document methodologic features (response rate)
define inferential statistics
- Make inferences about a population
- Answer the research questions
what are the four levels of measurement
- nominal
- ordinal
- interval
- ratio
what is nominal
Mutually exclusive categories/groups. Assigning numbers to classify characteristics into categories (categorical); Ex: gender, blood type, marital status
what are the two subcategories of nominal
- equivalence/non-equivalence
- mutually exclusive/collectively exhaustive
what is equivalence/non-equivalence in terms of nominal
It only provides info about equivalence and nonequivalence.
Ex: male = 1, female = 2; So jenny is equivalent to 2 (female) but not equivalent to male
what is mutually exclusive/collectively exhaustive in terms of nominal
each person must be classifiable into one and only one category.
Ex: 1 = married, 2 = divorced, 3 = widowed. The requirement for collective exhaustiveness would not be met if there were people in a sample who had never been married
which two levels of measurement are categorical
nominal & ordinal
what is ordinal
Ranked groups; Sorting people based on their relative ranking on an attribute. Ordered according to some criterion. Captures equivalence but also relative rank; Ordered/Relative ranking
They do not however tell us anything about how much greater on elevel is than another; The differences between the rankings are unknown
what is an example of ordinal
Ex: 1 = completely independent; 2 = needs another person’s assistance; 3 = completely independent; Signifies incremental ability to perform ADLs; People coded 4 are equivalent to each other with regard to functional ability and relative to those in other categories, have more of that attribute
what is interval
Equal numerical distance between points on the scale; Expands analytic possibilities (i.e. data can be averaged meaningfully)
what is an example of interval
temperature
what is ratio
Interval level data which has a true zero (absence of a factor); Highest measurement level; Provides info about ordering on the critical attribute, the intervals between objects, and the absolute magnitude of the attribute because they have a rational meaningful zero
what is an example of ratio
Ex: weight (has an absolute 0)
what two level of measurements are continuous
interval & ratio
when looking at mode, counts and frequency, which level of measurement could you use
nominal, ordinal, interval or ratio
when looking at median, minimum, maximum, range, which level of measurement could you use
ordinal, interval or ratio
when looking at mean, variance, standard deviation, which level of measurement could you use
interval or ratio
t/f - interval and ratio are the same statistics
true - but ratio is an absolute 0
which level of measurement should you use for age
nominal or ordinal
what are the measures of central tendencies
mode, mean, median
what is mode
the most frequent value
Frequency distribution: observed scores values and the frequency (%)
what is median
the midpoint-above/below 50%
Average position, preferred with highly skewed data
what is mean
the average
Affected by every score
Most widely used
most stable
what are the three shapes of distribution
- symmetric
- asymmetric
- modality
what is a symmetric distribution
Normal distribution (bell curve)
what is asymmetric distribution
(pulled towards a tail - look at tail not hump to describe +/-
Positively skewed - tail points to the right
Negatively skewed - tail points to the left; Ex: death would be negatively skewed because people die at an older age and only a few die young
in positively skewed, which way does the tail point
right
in negatively skewed, which way does the tail point
left
what are the two types of modality distribution
unimodal and multimodal
what is unimodal distribution
only one peak (i.e. a value with high frequency)
what is multimodal distribution
more than one peak
what is variability
how spread out the data are
what is range
highest value - lowest value
ex: blood pressure
what is variance
- value of the SD before the square root has been taken
- spread/dispersal of data
what is standard deviation
the average amount of deviation of values from the mean using every score
what does a lower standard deviation mean
the more homogenous the sample is (sharper peak at the top)
what does a higher standard deviation mean
be more variability and more heterogeneity in the variable that you’re interested
what does standard deviation look like in a near-normal distribution
Line in middle is mean
+/- 3 SDs above and below the mean
68% of cases fall within 1 SD
+/- 1 SD = above (34%), below (34%) (Shaded area)
+/- 2 SD = 95% - usually anything outside of 2 SDs is going to be an outlier
+/- 3 SD = 99.7%
What is the key thing that makes experimental or quasi-experimental studies different from non-experimental designs? A. Demographic variables B. Intervention or treatment C. Number of groups D. Sample size
B. Intervention or treatment
What type of design is a systematic investigation of relationships between two or more variables that is meant to explain relationships between variables instead of establishing cause and effect? A. Randomized clinical trial (RCT) B. Correlational design C. Experimental design D. Quasi-experimental design
B. Correlational design
Which design includes the administration of more than one treatment to each subject with the treatments being provided sequentially rather than concurrently? A. Crossover B. Descriptive C. Factorial D. Time series
A. Crossover
The aim of a study is to assess elementary school nurses’ perceptions of student bullying, actions when they encounter bullies, and perceived level of preparation for dealing with this problem. Which design would be most appropriate to use? A. Crossover B. Descriptive C. Experimental D. Prospective (cohort)
B. Descriptive
The aim of a study is to evaluate the short- and long-term effects of smoking cessation strategies tailored to help pregnant adolescents attain and maintain abstinence from smoking. Specifically, the researchers want to compare differences in short and long term smoking behaviors in three groups (Teen Fresh Start, Teen Fresh Start Plus, and Usual Care control). What design would be most appropriate to use? A. Case control B. Crossover C. Descriptive D. Experimental
D. Experimental
The aim of a study is to examine the relationship of less restrictive restraints with seclusion usage, average years of nursing experience, and mix of staff nursing degrees. What design would be most appropriate to use? A. Case Control B. Crossover C. Descriptive correlational D. Randomized controlled trial
C. Descriptive correlational
