Validity, Reliablity, Standardization, Generalization, Experimentation In Psychology


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Validity, Reliablity, Standardization, Generalization, Experimentation In Psychology

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Validity, Reliablity, Standardization, Generalization, Experimentation In Psychology

  1. 1. VALIDITY: What is validity? Validity is an attribute of your inference, not the instrument itself, which may be more valid for some inferences and/or populations than others (e.g. self-esteem survey in Latin). What’s more in validity? Now I’d like to share some more about validity. Validity: A valid argument is one in which it is not possible for the conclusion to be false if the premises are true. This is a very daring statement, not about what is actually the case, but about what could possibly be the case. It is cooperative, when considering validity, to consider the notion of possible worlds. I can picture a possible world in which grass is blue, and I can picture a possible world in which trees are blue. But think about the following argument: Premise: If grass is blue, then trees are blue. Premise: Grass is blue. Conclusion: Trees are blue. We can add more stuff in validity. The validity of an argument should be distinguished from the genuineness of the conclusion. If one or more of the premises is false, the conclusion of a valid argument may be false. I’d like to give an example. “All mammals are four-footed animals; all people are mammals; therefore, all people are four-footed animals” is a valid argument with a false conclusion. On the other hand, an invalid argument may by possibility have a true conclusion. “Some animals are two- footed; all people are animals; for that reason, all people are two-footed” happens to UNIVERSITY OF MANAGEMENT AND TECHNOLOGY
  2. 2. have a true conclusion, but the argument is not valid. Logical validity depends on the form of the argument, not on its content. If the argument were valid, some other term could be substituted for all occurrences of any one of those used and validity would not be affected. By substituting “four-footed” for “two-footed,” it can be seen that the premises could both be true and the conclusion false. Thus the argument is invalid, even though it has a true conclusion. RELIABILITY: What is reliability? The extent to which the same result is achieved when a measure is repeatedly applied to the same group. One more definition I’d like to present is “In assessment, the consistency of an assessment outcome; for example, different assessors using the same evidence making the same judgment, or the same assessor making the same judgment about the same evidence on different occasions.” According to St-Andrews university’s psychology department reliability is “The consistency with which a measuring instrument (such as a psychometric test) performs its' function, gauged, for example, by comparing test scores from the same subjects at different times.” What’s more in reliability? Reliability refers to the consistency of a measure. An analysis is considered reliable if we obtain the identical product constantly. For example, if a test is planned to measure a trait (for instance introversion), then each time the test is administered to a subject, the results should be just about the same. Unluckily, it is impossible to calculate reliability accurately, but there are more than a few different ways to guess reliability. Examples of reliability: Susie returned her friend’s bike the at • 3:00, just as she’d promised. Eddie sorted the laundry exactly as his • mother had shown him how to do. Jim phoned his friend, Ben to say that he would be a half hour late because his • UNIVERSITY OF MANAGEMENT AND TECHNOLOGY
  3. 3. mom had to drop his brother off at hockey first. Chris did the dishes even though he was not in the mood. • Karen was asked to bring felts for her group project and she knew that she had • none at home, so she made sure to borrow them off of a friend before class. Justification of examples: In each of the above examples, people are shown keeping their commitments to the best of their abilities. In the first example, Susie is sure to return something that she has rented at the accurate time she said she would. A vital part of being reliable is that you are unsurprisingly dependable and others do not need to be anxious that what they have asked you to do will be completed. In this case, Susie’s friend is sure to lend her the bike another time since she does not need to worry that it will be back on time. Another part of being reliable is treating jobs like they are a sacred trust, no matter how small that job may seem to be. Eddy’s mother has shown him how to sort the laundry before and he knows that it is important to her that it is done the correct way, so he is sure to try his best. Sometimes, when you are trying to do what you have promised, things come about that are out of your control, as we can see in the third example. It is not Jim’s fault that he is going to be late, but he still makes sure to let his friend know what is going on. In the fourth example, Chris has said that he would do the dishes, but later does not feel like it. He is showing reliability because he does it anyway because his parents are counting on him to do his part of the family chores. In the last example, Karen overcomes an obstacle by Planning ahead. Instead of giving up on her commitment and hoping that she can use another student’s supplies, she has done everything in her power to make sure that she sticks with her promise. GENERALIZATION: What is Generalization? The ability to take information, rules, and strategies learned about one situation and apply it appropriately to other, similar situations. It can also be defined as “transfer of a response learned to one stimulus to a similar stimulus” More in Generalization: After an animal has learned a conditioned response to one stimulus, it may also respond to similar stimuli without further training. If a child is bitten by a large black dog, the UNIVERSITY OF MANAGEMENT AND TECHNOLOGY
  4. 4. child may fear not only that dog, but other large dogs. This phenomenon is called generalization. Less similar stimuli will usually produce less generalization. For example, the child may show little fear of smaller dogs. Here comes the concept of conditioning which is of two types. 1. Classical Conditioning 2. Operant Conditioning Classical Conditioning: It’s the form of learning in which a reflexive or automatic response transfers from one stimulus to another. For instance, a person who has had painful experiences at the dentist’s office may become afraid at just the sight of the dentist’s office building. Fear, a natural reaction to a painful stimulus, has shifted to a different stimulus, the view of a building. Most psychologists accept as true that classical conditioning take place when a person shapes a mental relationship between two stimuli, so that encountering one stimulus makes the person think of the other. People are inclined to form these mental relations between measures or stimuli that occur strongly together in space or time. Operant Conditioning: One of the most widespread and important types of learning is operant conditioning, which involves increasing a behavior by following it with a reward, or decreasing a behavior by following it with punishment. For example, if a mother starts giving a boy his favorite snack every day that he cleans up his room, before long the boy may spend some time each day cleaning his room in anticipation of the snack. In this example, the boy’s room-cleaning behavior increases because it is followed by a reward or reinforce. UNIVERSITY OF MANAGEMENT AND TECHNOLOGY
  5. 5. THIS PICTURE IS TAKEN FROM AN EXPERIMENT. IT IS NOT THE PART OF THE CURRENT TOPIC BUT JUST TO SHOW SOMETHING OUT OF IT. Unlike classical conditioning, in which the conditioned and unconditioned stimuli are presented regardless of what the learner does, operant conditioning requires action on the part of the learner. The boy in the above example will not get his snack unless he first cleans up his room. The term operant conditioning refers to the fact that the learner must operate, or perform a certain behavior, before receiving a reward or punishment. EXPERIMENTATION: What is Experimentation? It is the process of testing a hypothesis by collecting data under controlled, repeatable conditions. We can also describe the same thing as “A method of research which permits the inference of cause and effect. At least two groups of subjects are treated exactly alike in all ways except one, the independent variable. Differences in the behavior of the Experimental and Control group which cannot be accounted for by experimental error are then attributed to the effect of the experimental treatment.” UNIVERSITY OF MANAGEMENT AND TECHNOLOGY
  6. 6. What is more in Experimentation? To learn more about experimentation, we need to study Milgram Experiment. It gives us the more accurate information about the experimentation. For example, it is through experiments that we know that drinking alcohol causes slower reaction times. The experimenter can give a set amount of alcohol to a group of participants, then measure their reaction times. If their time slows down after drinking the alcohol, we know the alcohol caused that effect. Milgram Experiment: During the 1960s, American psychologist Stanley Milgram studied a form of social influence stronger than conformity: obedience to authority. In a famous series of experiments that attracted controversy about human research ethics, Milgram put each of 1,000 subjects into a situation in which they were ordered by an experimenter to administer painful electric shocks to a confederate (who did not actually receive any shocks). The subjects in these studies were led to believe that they were acting as 'teachers' in a study of the effects of punishment on learning. Each time the 'learner' made a mistake on a memory test, the subject was supposed to deliver a shock. The intensity of the shocks was to increase, beginning at 15 volts and continuing in 15- volt increments to 450 volts. In most situations, the subjects could not actually see the learner, but they could hear an audio taped response that sounded increasingly serious with each successive shock. The learner's protests would begin with grunts of pain, progress to shouting and sometimes even complaints of heart trouble, and eventually turn to agonized screams of “Let me out of here!” After the teacher passed the 330-volt level, the learner would fall silent and give no further responses. Yet at each step, an experimenter ordered the subject to raise the level of shock to the learner. Many of the subjects in the experiment felt extreme anguish over the pain they thought they were inflicting. They sweated, trembled, bit their lips, or broke into fits of nervous laughter. Despite their distress, an astonishing 65 percent of subjects in Milgram's initial study delivered the final punishment of 450 volts. Other social psychologists conducting similar experiments later observed comparable levels of obedience among men and women all over the world. Apparently, many otherwise decent people will cause intense suffering to others rather than disobey authority. Milgram designed this experiment in order to understand the obedience of Nazi soldiers and officials in killing millions of Jews and others during World War II. When interviewed UNIVERSITY OF MANAGEMENT AND TECHNOLOGY
  7. 7. after the experiment, many of Milgram’s subjects said that they had obeyed largely because they thought the experimenter would bear responsibility for any harm to the learner. Similarly, Nazi death camp administrator Adolph Eichmann, when tried for murdering thousands of innocent people, attributed his behavior to the fact that he was merely following the orders of his superiors. ependent Variable: A dependent variable is what you measure in the experiment and what is affected during the experiment. The dependent variable responds to the independent variable. It is called dependent because it quot;dependsquot; on the independent variable. In a scientific experiment, you cannot have a dependent variable without an independent variable. Example: You are interested in how stress affects heart rate in humans. Your independent variable would be the stress and the dependent variable would be the heart rate. You can directly manipulate stress levels in your human subjects and measure how those stress levels change heart rate. Independent Variable: An independent variable is the variable you have control over, what you can choose and manipulate. It is usually what you think will affect the dependent variable. In some cases, you may not be able to manipulate the independent variable. It may be something that is already there and is fixed, something you would like to evaluate with respect to how it affects something else, the dependent variable like color, kind, time. Example: You are interested in how stress affects heart rate in humans. Your independent variable would be the stress and the dependent variable would be the heart rate. You can directly manipulate stress levels in your human subjects and measure how those stress levels change heart rate. STANDARDIZATION: What is Standardization? It can be defined in simple words as the process of formulating, issuing and implementing standards. What’s more in Standardization? The questions arises that how much standardization is important in testing process? Steadiness and objectivity of how tests are managed and scored. With the aim of evaluating one person to another on a test, it’s very essential that they must take the test under the same situation and the same scoring course of action is applied to both. For example, suppose one person took a English test in a heavy shower and the other UNIVERSITY OF MANAGEMENT AND TECHNOLOGY
  8. 8. in a silent proof room. Based on the test scores, can we guess who can be the good in English? Or it is good to say, that heavy shower confused the person? Let us more talk about it that we applied different scoring criteria to each of the test takers. Could we still say who was fine in English? This is way standardization is so important in testing. CORRELATION: What is Correlation? A measure of linear association between two (ordered) lists where two variables can be strongly correlated without having any causal relationship and two variables can have a causal relationship and yet be uncorrelated. There are two types of Correlation. 1. Positive Correlation 2. Negative Correlation Positive Correlation: In positive correlation, if one factor is increasing, then other factor related to the first would also be increasing and vice versa. In other words, we can take positive correlation as Positive correlation indicates that both variables increase or decrease together, whereas negative correlation indicates that as one variable increases, so the other decreases, and vice versa. We can understand it by very simple examples. Example: According to psychological term, when illness increases depression increases. When illness decreases, depression decreases. The above example can also be demonstrated by the image given below. UNIVERSITY OF MANAGEMENT AND TECHNOLOGY
  9. 9. Negative Correlation: In a negative correlation, as the values of one of the variables increase, the values of the second variable decrease. Likewise, as the value of one of the variables decreases, the value of the other variable increases. Here are some other examples of negative correlations: 1. Education and years in jail—people who have more years of education tend to have fewer years in jail (or phrased as people with more years in jail tend to have fewer years of education) 2. There is a negative correlation between TV viewing and class grades—students who spend more time watching TV tend to have lower grades (or phrased as students with higher grades tend to spend less time watching TV). UNIVERSITY OF MANAGEMENT AND TECHNOLOGY