{"id":4468,"date":"2018-10-07T00:54:02","date_gmt":"2018-10-07T04:54:02","guid":{"rendered":"https:\/\/www.amyork.ca\/academic\/zz\/?p=4468"},"modified":"2018-10-07T01:11:28","modified_gmt":"2018-10-07T05:11:28","slug":"experimental-design-psychological-research","status":"publish","type":"post","link":"https:\/\/www.amyork.ca\/academic\/zz\/cognitive-psychology\/experimental-design-psychological-research\/","title":{"rendered":"Experimental Design: Psychological Research"},"content":{"rendered":"

Goals of Scientific Research:<\/u><\/p>\n

    \n
  1. Description of behavior<\/li>\n
  2. Prediction of behavior<\/li>\n
  3. Determination of the causes of behavior<\/li>\n
  4. Explanations of behavior<\/li>\n<\/ol>\n

    Three Types of Scientific Studies:<\/u><\/p>\n

      \n
    1. Controlled studies<\/li>\n
    2. Correlational studies<\/li>\n
    3. Descriptive studies<\/li>\n<\/ol>\n

      Controlled Studies (true experiments):<\/u><\/strong><\/p>\n

      Random Assignment<\/u>:<\/p>\n

      -Taking subjects and randomly assigning them to groups; this controls for extraneous variables -No bias<\/p>\n

      -No differences between groups<\/p>\n

      Independent Variable:<\/u><\/p>\n

      -The variable a researcher is interested in and manipulates Pex: the food given)<\/p>\n

      Dependent Variable:<\/u><\/p>\n

      -The variable the experimenter measures; outcome<\/p>\n

      Example:<\/u><\/p>\n

      Hypothesis<\/em>: people who study for an exam while listening to music will score better than people who study in silence<\/p>\n

      Independent variable<\/em>: the music-listening Dependent variable<\/em>: test performance on the exam<\/p>\n

      2 Key Components of a Controlled Experiment:<\/u><\/p>\n

        \n
      1. Random Assignment<\/li>\n
      2. Identical Experimental Conditions<\/li>\n<\/ol>\n

        Random Sampling\/Selection<\/u><\/p>\n

        -the initial large group was randomly selected<\/p>\n

        Stratified Sample College Example<\/h2>\n

        -Randomly selected colleges and randomly select the same number of students from each college<\/p>\n

        -This is so you avoid being too specific \u2013 it needs to be generalizable<\/p>\n

        Correlational Studies<\/u><\/strong><\/p>\n

        -Patterns of co-occurrence between two observed events<\/p>\n

        -Ex: cigarette smoking and cancer<\/p>\n

        -Correlation does not equal causation<\/p>\n

        -There may be a third factor – it is hard to control for something in the real world<\/p>\n

        -Correlational studies are better ethically than controlled studies<\/p>\n

        Descriptive Studies<\/u><\/strong><\/p>\n

        -These studies just seek to describe an aspect of the world as it is<\/p>\n

        Design Flaws in Experimental Design:<\/u><\/strong><\/p>\n

        Clever Hans<\/h2>\n

        -A horse that could add and subtract, read German and answer simple questions by tapping his hoof<\/p>\n

        -The flaw: the horse would know when to stop and start tapping simply by getting cues from his owner Pextraneous factors)<\/p>\n

        Infants\u2019 Perception of Musical Structure<\/h2>\n

        -Infants turn their heads when they hear different music selections<\/p>\n

        -The flaw: the mothers influence their infants to change their head position when the mother also hears the music selection<\/p>\n

        -Solution: make the mothers wear headphones<\/p>\n

        Computers, Timing and Other Pitfalls<\/h2>\n

        -The computers do not guarantee updates and other mechanical means \u2013 it is good science to check things yourself and measure things on your own too.<\/p>\n

        Number of Subjects:<\/u><\/strong><\/p>\n

        Population<\/u><\/p>\n

        -The total group of people to which the researcher wishes to generalize findings<\/p>\n

        Homogeneous populations<\/h2>\n

        -All individuals are similar and alike<\/p>\n

        -You won\u2019t need to test too many people<\/p>\n

        Heterogeneous populations<\/h2>\n

        -Individuals are very different<\/p>\n

        -You will need to test everyone in the population Types of Experimental Designs:<\/u><\/strong><\/p>\n

        Between-Subjects Design Pindependent groups)<\/h2>\n

        -Each subject is in one condition only<\/p>\n

        Within-Subjects Design Prepeated measures) <\/u>-Each subject is tested in every condition<\/p>\n

        Advantages<\/u>:<\/em><\/p>\n

        –<\/em>smaller number of people required and you can test how each individual is affected by each manipulation<\/p>\n

        Disadvantages:<\/u><\/em><\/p>\n

        Demand characteristics<\/u>:<\/strong><\/p>\n

        -the subjects\u2019 performance can be influenced by a desire to make a certain condition work better Carry-Over Characteristics:<\/u><\/strong><\/p>\n

        -an effect that \u201ccarries over\u201d from one experimental condition to another Order Effects:<\/u><\/strong><\/p>\n

        -how a subject may be influenced by the order in which they do each condition<\/p>\n

        -i.e. the conditions are ordered in a certain way and a person may get influenced by stimuli presented to them<\/p>\n

        To Reduce Order Effects Prandom orders)<\/h2>\n

        -Use \u201cn factorial\u201d<\/p>\n

        -Latin Square PN x N) or PN x 2N)<\/p>\n

        4 Principle Ethical Considerations in Using Human Subjects:<\/u><\/strong><\/p>\n

          \n
        1. Informed consent: subjects need to agree to do the experiment<\/li>\n
        2. Debriefing: explain the experiment after it is over to the subject and answer questions<\/li>\n
        3. Privacy and Confidentiality: keep the subject\u2019s data and information confidential and stored<\/li>\n
        4. Fraud: researchers must not copy or create false data or allow it to be published<\/li>\n<\/ol>\n

          Quantitative Analysis (statistical analysis):<\/u><\/strong><\/p>\n

          Measurement Error:<\/u><\/p>\n

          -any difference between the observed value and the real or true value which leads to the skewing of results if not solved<\/p>\n

          -Between groups\/conditions differences<\/p>\n

          -The more measurements you take = the less measurement error<\/p>\n

          Performance Error:<\/u><\/p>\n

          -The subjects will not perform identically every time<\/p>\n

          Significance Testing:<\/u><\/p>\n

          -Uses a \u201cp value\u201d: the probability that the experimental result could have arisen by chance -Determines whether a result is repeatable<\/p>\n

          Alternatives to Classical Significance Testing:<\/u><\/p>\n

          -Bayesian inferencing<\/p>\n

          -Effect sizes<\/p>\n

          -Confidence intervals: determines a given probability of the range of values within the population parameters<\/p>\n

          -Meta-analyses<\/p>\n

          -Conditional probabilities: the probability of an event given that another event has already occurred<\/p>\n

          Null Hypothesis<\/h2>\n

          -predicts that the manipulation will have no effect at all<\/p>\n

          Qualitative Analysis (without significance testing):<\/u><\/strong><\/p>\n

          -Research whose findings are not arrived at by statistical or other quantitative procedures.<\/p>\n

          -Graph data and see what patterns emerge<\/p>\n

          -Line graph Pcontinuous); Bar graph Pcategorical); Bivariate Scatter Plot Ptwo continuous variables and how one affects the other<\/p>\n","protected":false},"excerpt":{"rendered":"

          Goals of Scientific Research: Description of behavior Prediction of behavior Determination of the causes of behavior Explanations of behavior Three Types of Scientific Studies: Controlled studies Correlational studies Descriptive… Continue Reading Experimental Design: Psychological Research<\/span><\/a><\/p>\n","protected":false},"author":4,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[113],"tags":[],"_links":{"self":[{"href":"https:\/\/www.amyork.ca\/academic\/zz\/wp-json\/wp\/v2\/posts\/4468"}],"collection":[{"href":"https:\/\/www.amyork.ca\/academic\/zz\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.amyork.ca\/academic\/zz\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.amyork.ca\/academic\/zz\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/www.amyork.ca\/academic\/zz\/wp-json\/wp\/v2\/comments?post=4468"}],"version-history":[{"count":0,"href":"https:\/\/www.amyork.ca\/academic\/zz\/wp-json\/wp\/v2\/posts\/4468\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.amyork.ca\/academic\/zz\/wp-json\/wp\/v2\/media?parent=4468"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.amyork.ca\/academic\/zz\/wp-json\/wp\/v2\/categories?post=4468"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.amyork.ca\/academic\/zz\/wp-json\/wp\/v2\/tags?post=4468"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}