CHAPTER 2 Flashcards
- Measures of Central Tendency
- Shapes of Distribution
Descriptive statistics
- Tell researchers where the center value (single value) lies in the distribution of data
- Most typical or most representative value of a given set of data
- Measures of CENTRAL TENDENCY
This is the average
MEAN
This is The number or average of the numbers in the middle
MEDIAN
This is The most frequently occurring value
MODE
It is the average of a set of data. To calculate this, find the sum of the data and then divide by the number of data.
Mean
It is the middle number in a set of data when the data is arranged in numerical order.
Median
The ____ is the number that occurs the most.
Mode
it is an average in which each observation in the data set is assigned or multiplied by a weight before summing to a single average value.
WEIGHTED MEAN
The participants’ scores on the Statistics test were analyzed. On average, participants scored (M = 78.56, SD= 10.34) indicating a moderate level of performance. This suggests a reasonable distribution of scores, with most participants scoring close to the mean.
Reporting the Mean in Research Articles (APA FORMAT)
It is score with an extreme ( very high or very low ) in relation to the other scores in the distribution
Outliers
it is a SHAPES OF A FREQUENCY DISTRIBUTION where Frequency distribution with one value clearly having a larger frequency than any other.
Unimodal Distribution
it is a SHAPES OF A FREQUENCY DISTRIBUTION where Frequency distribution with two approximately equal frequencies, each clearly larger than the others
Bimodal Distribution
it is a SHAPES OF A FREQUENCY DISTRIBUTION where Frequency distribution with more than two high frequencies separated by a lower frequency.
Multimodal Distribution
it is a SHAPES OF A FREQUENCY DISTRIBUTION where
Frequency distribution in which all values have approximately the same frequency
* No mode
Rectangular Distribution
it is a SHAPES OF A FREQUENCY DISTRIBUTION where Distribution in which the pattern of frequencies on the left and right side are mirror images of each other
* Bell shaped
* Normal distribution
Symmetrical Distribution
A Distribution in which the scores pile up on one side of the middle and are spread out on the other side. Distribution that is not symmetrical ( asymmetrical)
SKEWED DISTRIBUTION
A type of skewed distribution where
The peak (highest frequency) in the distributionis on the left hand side with tail tapering off the right
Positively Skewed Distribution
In skewed distribution it is a situation in which many scores or values pile up at the low end of a distribution( creating a skewness to the right) For example a test is difficult, students may get low scores, near zero, creating floor effect
Mean >Mdn>Mode
Floor effect
A type of skewed distribution where The peak (highest frequency ) in the distribution is on the right hand side with the tail tapering off the left
Ceiling effect – situation in which many scores pile up at the high end of a distribution ( creating a skewness to the left ) because it is not possible to have a higher score.
Mean<Median<Mode
Negatively Skewed Distribution
a type of curve Specific, mathematically defined, bell shaped frequency distribution that is symmetrical and unimodal
* Distribution observed in nature and in research commonly approximates it
NORMAL CURVE
Extent to which a frequency distribution deviates from a normal curve in terms of whether its curve in the middle is more peaked or flat than the normal curve.
KURTOSIS
TYPES OF KURTOSIS
- Leptokurtic
- Mesokurtic
- Platykurtic
scores are concentrated towards the mean ( Positive Kurtosis)
Leptokurtic-
A type of kurtosis where it is a normal curve
- Mesokurtic
A type of kurtosis where the scores have an extremely large deviation from the mean (Negative Kurtosis)
Platykurtic
