Chapter 4 Explanation Explanation Chapter 4 The logic of - PDF document

Chapter Outline Chapter Outline Three purposes of research Three purposes of research � � � � Exploration Exploration � � Description Description Chapter 4 � � Explanation Explanation Chapter 4 � The logic of nomothetic explanation The logic of nomothetic explanation � Criteria for nomothetic causality Criteria for nomothetic causality � � False criteria for nomothetic causality False criteria for nomothetic causality � � Research Design Research Design Necessary and sufficient causes Necessary and sufficient causes � � Units of analysis Units of analysis � � Individuals Individuals � � Groups Groups � � Organizations Organizations � � Social artifacts Social artifacts � � Faulty reasoning about units of analysis Faulty reasoning about units of analysis – – ecological fallacy and reductionism ecological fallacy and reductionism � � The time dimension The time dimension � � � � Cross- Cross -sectional studies sectional studies � � Longitudinal studies Longitudinal studies Approximating longitudinal studies � � Approximating longitudinal studies � � Elements of a research proposal Elements of a research proposal What are the three general purposes What are the two models of What are the three general purposes What are the two models of of research? explanation again? of research? explanation again? � Although it is worthwhile to distinguish different purposes of Although it is worthwhile to distinguish different purposes of � � Idiographic Idiographic - - aims at a complete understanding aims at a complete understanding � research, keep in mind that most studies will have more than research, keep in mind that most studies will have more than of a particular phenomena. of a particular phenomena. one purpose. one purpose. � Three general purposes: Three general purposes: � Example: Finding out what the Smith family plans Example: Finding out what the Smith family plans � � � Exploration Exploration - - Explore and develop some initial rough understanding of Explore and develop some initial rough understanding of � on filing for personal bankruptcy. There can be 20 on filing for personal bankruptcy. There can be 20 some phenomenon some phenomenon different reasons leading to that decision. different reasons leading to that decision. � Description Description – – Precise measurement and reporting of the characteristics Precise measurement and reporting of the characteristics � of some population or phenomenon under study. of some population or phenomenon under study. � Nomothetic Nomothetic - - aims at a general understanding aims at a general understanding � � Social sciences descriptions are usually more accurate and preci Social sciences descriptions are usually more accurate and precise than se than � casual observations. Answers the question of “what’s so”? casual observations. Answers the question of “what’s so”? of a class of phenomena. of a class of phenomena. � Explanation Explanation – – Discovery and reporting of relationships among different Discovery and reporting of relationships among different � aspects of phenomenon under study. aspects of phenomenon under study. � Example: Finding out the top 5 reasons why Example: Finding out the top 5 reasons why � � Answers the question of “why”. Answers the question of “why”. � people file for personal bankruptcy. people file for personal bankruptcy. What are the three criteria for What are the three criteria for What are necessary and sufficient What are necessary and sufficient nomothetic causality? nomothetic causality? causes? causes? � Variables must be correlated. Variables must be correlated. � Necessary cause represents a condition that must be present Necessary cause represents a condition that must be present � � for the effect to follow. for the effect to follow. � Example: Education level of parents are found to be correlated t Example: Education level of parents are found to be correlated to o � education level of their children. education level of their children. � Rule: A must be true for B to be true. Thus A is a necessary cau Rule: A must be true for B to be true. Thus A is a necessary cause for se for � � Cause takes place before the effect. Cause takes place before the effect. B. B. � � Example: Being pregnant is a necessary cause for giving birth to Example: Being pregnant is a necessary cause for giving birth to a a � � Example: Education level of parents usually is determined BEFORE Example: Education level of parents usually is determined BEFORE � child. child. the education level of their children. Thus the education level of parents the education level of their children. Thus the education level of parents is likely to be the cause in this relationship. is likely to be the cause in this relationship. � Sufficient cause represents a condition that if present, Sufficient cause represents a condition that if present, � � Effect cannot be explained in terms of a third variable Effect cannot be explained in terms of a third variable guarantees the effect in question. guarantees the effect in question. � (nonspurious). (nonspurious). � Rule: If A is true, B must be true. Thus A is a sufficient cause Rule: If A is true, B must be true. Thus A is a sufficient cause for B. for B. � � Example of a spurious relationship: Ice cream sales are positive Example of a spurious relationship: Ice cream sales are positively ly � Example: Not taking the final exam (thus getting 0 point on the Example: Not taking the final exam (thus getting 0 point on the final) is final) is � � a sufficient cause for failing this class. correlated with number of people drown at the beach. And ice cream correlated with number of people drown at the beach. And ice cre am a sufficient cause for failing this class. eating happens before the drowning. But is eating ice cream causing eating happens before the drowning. But is eating ice cream caus ing � Causes that are necessary and sufficient are the most satisfying Causes that are necessary and sufficient are the most satisfying � people to drown? No, because there is a third factor: hot weather. Hot people to drown? No, because there is a third factor: hot weathe r. Hot outcome in research. However, in social science research, outcome in research. However, in social science research, weather cause ice cream consumption to go up, and number of people weather cause ice cream consumption to go up, and number of peop le these clear- these clear -cut causal relationships are rare. cut causal relationships are rare. swimming to go up at the same time. Hot weather, in this case, has swimming to go up at the same time. Hot weather, in this case, h as caused a spurious relationship between ice cream consumption and caused a spurious relationship between ice cream consumption and number of people drown. number of people drown. 1