• Shuffle
Toggle On
Toggle Off
• Alphabetize
Toggle On
Toggle Off
• Front First
Toggle On
Toggle Off
• Both Sides
Toggle On
Toggle Off
Toggle On
Toggle Off
Front

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

Play button

Play button

Progress

1/65

Click to flip

65 Cards in this Set

• Front
• Back
 Definition Descriptive Statistics Serves as a tool to describe or summarize or reduce to manageable form. Definition Quantitative Measures of height, weight, time, etc... Dealing with numbers Definition Qualitative Gender, college major, type of pet, etc...Dealing with descriptors Definition Inferential Statistics Purpose is to predict or estimate characteristics of a population from a knowledge of the characteristics of only a sample of the population Definition Population Any group of persons having a defined characteristic Definition Sample A portion of the population Definition Variable Any observation that can take different values (e.g. gender or race) Definition Attribute A specific value on a variable (e.g. female or male) Definition Measurement Transforms attributes into more tractable things, numbers. What are the Measurement Scales Nominal Ordinal Interval Ratio Definition Nominal Measurements -lowest level of measurements -Grouping or categorizing with respect to some attribute/quality -Anything that can be placed into a category -Code with numbers Examples Nominal -College Major -ethnicity -Gender -Eye Color Definition Ordinal Measurements -RANKING -ranks an attribute -a level above nominal -possible with different amounts of an attribute Examples Ordinal -Class Ranking -Order of people crossing the finish line -Rank of feeling on a scale Definition Interval Measurement -Describe the size/attribute of the differences amoung things -Zero= NOT correspond to absence of variable measured Examples Interval -Temperature -Calendar year Definition Ratio Measurement -Highest level of measurements -same as interval BUT zero=the absence of the property being measured Examples Ratio -Age -Height -Weight -distance -Time Definition Continuous Variable A variable that can assume an infinite number of whole and fractional values e.g. weight, age, & reaction time Definition Discrete Variable A variable where measurement can take on only separated values and can only assume whole numbers e.g. number of children in the family Definition Parametric Statistics Deals with the use of means and standard deviations and requires that the variables measured be of INTERVAL or RATIO data types Definition Nonparametric Statistics Deals with frequency counts or ranking of the measured variable Requires that the measured variable be NOMINAL or ORDINAL Definition Independent Variable "Grouping" The experimental variable or the treatment variable. It is manipulated in some manner so it may be described in that manner Definition Dependent Variable Used to describe the varibales being measured or the variable of interest (research/outcome variable) Definition Measures of Central Tendency Describe typical, average, or representative scores Convey info about the center of a distribution of a set of scores Most widely used of all statistical descriptions of data What are the common types of measures of central tendency -Mode -Median -Mean Definition Mode The score or observation that occurs most frequently -appropriate for ANY variable and may be used with ALL data types (especially with nominal) Definition Median The 50th percentile of a distribution. The midpoint of the distribution -equal number of observations above and below the median. -You have to rank the scores in order (high-low, low-high, etc...) What can Percentile Rank be used for? Often used for establishing things like obesity in growing children Definition Mean The arithmetic average of a set of numbers -every score in the distribution is used in calculating the mean. -most widely used of the central tendency -the foundation for statistical concepts Definition Trimmed Mean A mean calculated with the lowest and highest scores discarded. What are the 2 most important statistical characteristics of any distribution of scores 1)Central Tendency 2)Variablility What are the types of Variability -range -variance -standard deviation Definition Range The difference between the largest and smallest scores in a distribution (and only these two scores) Problems: Outliers increase ranges & little to no value in inferential statistics Definition deviation scores Reflect something about the degree of variation in a set of scores Definition Sum of Squares to square each deviation and then sum the squared deviation scores (instead of working with the absolute value of the deviation scores). Definition Variance The mean of the squared deviation scores divided by the degrees of freedom, also known as the MEAN SQUARE Not very useful in descriptive measure Definition Degrees of freedom Number in the sample minus one. represents the number of scores that are free to vary Definition Standard Deviation The square root of the variance. -Extensively used in descriptive statistics -most commonly used measure of the variability of the scores What is a graph A visual representation that are used to describe the characteristics of a distribution of scores Definition Rank Order Distribution A method where the scores are put in order from high to low Definition Simple Frequency Distribution a method where the frequency of scores at each value of the variable are listed -Works well when the range of the score is small Definition Group Frequency Distribution a method where the frequency of scores are grouped into classes or intervals If the range scores is large which distribution is best? Grouped Fredquency Distribution How many intervals is best in a data? 10-20 intervals If a range of scores is great how does it affect the intervals? More intervals What happens when info/data is put is grouped into intervals? information loss.. fewer the intervals, the greater the loss How many intervals? this question is answered by some compromise b/n the importance of precision and the ease of the interpretation for the intended audience Once you have a freq. distribution what is the best way to display that data? in the form of a table most common methods of graphing -histogram -frequency polygon -ogive curve (cummulative freq. polygon) Frequency polygon is.. similar to a histogram but a line graph is used- data is sometimes presented in the form of presentages Cumulative Freq. Polygon = Ogive curve -Principal value of this type of graph is that info is arranged in such a way the percentile rank of any observation can be easily estimated Types of distributions: Normal -symmetrical- 50% on each side - bell shaped -mean, median, mode are equal -if we know the mean & standard deviation, each individual's performance on the dependent variable can be evaluated -numerous variables are normally distributed or approximately so (IQ scores, heightof adult women, etc.) Other types of distributions -bimodal -multomodal -rectangular (no true mode) -skewed distributions (positive/negative) Unimodal distribution one mode as in the normal distribution -mean, median and mode = equal bimodal distriubtion two modes in distribution multimodal three or more modes in skewed distributions what happens to the mean? -positively skewed- mean will be larger than the median or mode -Negatively skewed- mean will be smaller than the median or mode In skewed distributions where is the median? between mode and mean (usually closer to the mean) What incr. as the magnitude of the skewdness increase? -degree of symmetry -differ among mena, median & mode Skewedness = ? 3(Mean- Median)/standard devitaion Kurtosis measure of reltive peakedness in a curve Platykuric flat, broad Leptokuric distribution slender, narrow what does degrees of freedome fix in a data set? it corrects for sampling error