PSY 230 Final Study Guide

• You are enjoying a relaxing hike when the answer to a problem you have been struggling with for days and had put aside suddenly reveals itself. This method of knowing is called the: method of intuition
• This method of knowing uses both reasoning and intuition but relies on objective assessments. Hypothesis testing is an essential step in the use of this method. This method is: scientific method
• This method of knowing uses reason alone to arrive at knowledge often using syllogisms in which a major premise and a minor premise are followed by a conclusion. This method of knowing is called: method of rationalism
• A researcher is exploring the effect of classroom environments on learning. Two identical PSY230 courses are being taught by the researcher. One is taught in a room with glass walls which allows students to see people walking past, the other is in a similarly configured room with opaque walls. Students learning is assessed at the end of the semester with an exam. The independent variable is : class environment (wall)
• A researcher is exploring the effect of classroom environments on learning. Two identical PSY230 courses are being taught by the researcher. One is taught in a room with glass walls which allows students to see people walking past, the other is in a similarly configured room with opaque walls. Students learning is assessed at the end of the semester with an exam. The dependent variable is : score on exam
• Observational studies can be used to determine causality : False
• True experiments, which include manipulation of the independent variable, measurement of the dependent variable, and random sampling can be used to determine causality : True
• Descriptive statistics are connected with techniques that are used to describe or characterize the obtained data
• Inferential statistics are concerned with techniques that are used to infer the characteristics of a population based on sample data
• What are two important benefits of random sampling?

  Allows laws of probability to be applied to data / helps achieve a sample that represents the population
• In statistical notation, the N stands for?

  total number of subjects or scores
• What scale has categories for units?

  Nominal
• The values on this scale represent rank ordering : Ordinal
• What scale has equal intervals between adjacent units but does NOT have an absolute zero?

  Interval
• What scale has equal intervals between adjacent units but DOES have an absolute zero?

  Ratio
• The celsius scale of temperature is an example of a variable measured on the interval scale
• What type of variable theoretically can have an infinite number of values between adjacent units on the scale?

  Continuous
• The real limits of a continuous variable are those values that are above and below the recorded value by one-half of the smallest measuring unit of the scale.
• How many decimal places do you carry all calculations to?

  two or more
• What does a relative frequency distribution indicate?

  the proportion of the total number of scores that occur in each interval
• What does a cumulative frequency distribution indicate?

  the number of scores that fall below the upper real limit
• What does a cumulative PERCENTAGE distribution indicate?


  the percentage of scores that fall below the upper real limit
• The percentile rank of a score is the percentage of scores with values lower than the score in question
• The abbreviation i means : the interval width
• Frequency distributions of nominal or ordinal data are customarily plotted using a : bar graph
• What differentiates a bar graph from a histogram?

  the bars touch on a histogram
• What type of graph uses points placed at the midpoint of class intervals which indicate the frequencies of each class interval?

  frequency polygon
• What does it mean if a curve has most of the scores occur at higher values of the x-axis and the curve tails off towards the end?

  negatively skewed
• What are the 4 methods of truth?

  Authority, Rationalism, Intuition, Scientific Method
• What are the 4 measurement scales?

  1. Interval: Absent zero 2. Nominal: labels, no numbers 3. Ordinal: categories by size 4. Ratio: Absolute zero
• Given a set of scores (N), dividing the sum of the scores by N would give you the : arithmetic mean
• What is NOT a property of the mean?

  The mean is the most sensitive to sampling variation
• The median is defined as the scale value below which 50% of the scores fall
• The deviation score tells you how far away the raw score is from the mean.
• The square root of the variance will give you the : standard deviation
• When calculating sample SD we divide SS by N-1 rather than N to make it a more accurate estimate of the population SD
• X-bar means what?

  the mean of the variable X
• X minus mu would give you?

  a deviation score for population data
• Approximately 68 percent of the values under a normal curve fall within 1 SD of the mean
• The mean of a z distribution has a value of : 0