Data Handling And Analysis Flashcards
what is primary data?
- information collected directly from first-hand experience
- specifically relates to purpose of the study
- collected from interviews, observations, questionnaires etc
what would collecting primary data involve?
- designing a study
- gaining ethical approval
- piloting the study
- recruiting and testing participants
- analysing data and drawing conclusions
what is a strength of primary data?
data collection is designed so it fits purpose of study
what is a limitation of primary data?
time-consuming and expensive
what are the 2 types of primary and secondary data?
quantitative and qualitative data
what is secondary data?
data was collected for a purpose other than the current study
what can secondary data include?
- conducting met-analysis on data
- review studies use secondary data
what are the strengths of secondary data?
- simper and cheaper, less time consuming
- data may already have been subjected to statistical testing (known if its significant)
what is a limitation of secondary data?
data may not exactly meet needs of the study
what is quantitative data?
numerical data
what is qualitative data?
non-numerical data
(open questions, interviews etc.)
what are descriptive statistics?
- they summarise quantitative data
- involves measures of central tendency, measures of dispersion, graphs and charts
what is the nominal level of measurement?
data can be placed or counted into different categories
what is the ordinal level of measurement?
- data is ranked in order or rated on a scale
- when using scale, points may be labelled
- is subjective and each point on ordinal scale are not same value
what is the interval level of measurement?
- interval scale orders measurements
- intervals are equal - based on standard unit of measurement
what is the ratio level of measurement?
like interval data but has a genuine zero point
what are the measures of central tendency?
mean, median, mode
what is the mean, median and mode?
mean - arithmetic average
median - middle value when numbers are in order
mode - most common value
what are the advantages of using the mode?
- represents figure that occurs in data
- useful when other measures of central tendency are meaningless
- unaffected by 1 or 2 extreme scores
what are the disadvantages of using the mode?
- doesn’t tell us anything about other values
- not always a single mode
- small changes in data can radically alter mode
what are the advantages of using the median?
- relatively unaffected by extreme values
- can be used on data with skewed distributions
what are the disadvantages of using the median?
- doesn’t work well in small data sets
- ignores most scores
- affected by alteration of central values
what are the advantages of using the mean?
most powerful measure of central tendency
what are the disadvantages of using the mean?
- can’t be used on skewed data that has anomalies
- can give misleading average
- inappropriate to use on ordinal & nominal data
what are the characteristics of a normal distribution curve?
- symmetrical, bell-shaped
- mean, median, mode at same point
- dispersion of scores either side of midpoint
what is a negative skew?
- the highest point is to the right of the center
- mean has lower value than mode & median
- affected by lots of HIGH scores
what is a positive skew?
- highest scores are to the left of the center
- mean has higher value than mode & median
- affected by lots of LOW scores
in a negative skew, where are the mean, median and mode?
mean (left) - lower end
median (middle)
mode (right) - higher end
in a positive skew, where are the mean, median and mode?
mean (right) - lower end
median (middle)
mode (left) - higher end
what are investigator effects?
occur when a researcher unintentionally, or unconsciously influences the outcome of any research they are conducting
what are pilot studies?
small, trial versions of proposed studies to test their effectiveness and make improvements
what are the measures of dispersion?
range
standard deviation
what is the range?
difference between highest and lowest value of data set
what is an advantage of the range?
easy to calculate
what are the disadvantages of the range?
- only considers extreme values
- very sensitive to outliers
- doesnt tell us anything about middle scores/distribution
what is a standard deviation?
measures average distance of each score away from the mean
what is an advantage of standard deviation?
- most powerful measure of dispersion
- uses all scores in set of data in calculation
what is a disadvantage of standard deviation?
less effective when there are outlying scores that skew data
what are desriptive statistics?
used to describe the data and show a summary of the results
