研究设计实验研究的基本问题31.ppt

School of Public Administration Policy Dr. Kaifeng Yang ;问题;Given the research question, what type of evidence is needed to answer the question (or test the theory) in a convincing way?;Why?Making decisions to ensure validity;;;;School type;When you observe X and Y co-vary, the reason may be:;Coping with Rival Hypotheses;The New Design;问题;Pretest ;;Staging Experiments;Key Features of Experimental Approach;Random Assignment vs. Random Sampling;Experimental Design;Pretest ;Pre-experimental vs. True Experimental Designs;Pre-experimental Designs;True Experimental Designs;True Experimental Designs (2);Quasi-experimental Designs;Quasi-experimental Designs;Quasi-experimental Designs (3);Experimentation Outside the Laboratory;问题;Experiment as a Social Occasion;Minimizing Bias Due to the Social Nature of Experimentation;Research Design Validity;Internal Validity;Example: Imagine that we are studying the effects of a compensatory education program in mathematics for first grade students on a measure of math performance such as a standardized math achievement test;Threats to Internal Validity;;External Validity: Representativeness;External Validity: Generalizability;Next Week;lXp#s%v)y0B3F6IaLdOgSjVmYq!tw-z1D4G7JbMePhTkWoZr$u(x+A2E5H9KcNfRiUlXp#sv)y0C3F6IaLdPgSjVnYq!t*w-A1D4G8JbMeQhTlWoZr%u(x+B2E6H9KcOfRiUmXp#sv)z0C3F7IaLdPgSkVnYq$t*w-A1D5G8JbNeQhTlWo#r%u(y+B2E6H9LcOfRjUmXp!sw)z0C4F7IaMdPhSkVnZq$t*x-A1D5G8KbNeQiTlWo#r%v(y+B3E6H9LcOgRjUmYp!sw)z1C4F7JaMdPhSkWnZq$u*x-A2D5H8KbNfQiTlXo#s%v(y0B3E6I9LdOgRjVmYp!tw)z1C4G7JaMePhSkWnZr$u*x+A2D5H8KcNfQiUlXo#s%v)y0B3F6I9LdOgSjVmYq!tw-z1D4G7JbMePhTkWoZr$u(x+A2E5H8KcNfRiUlXp#s%v)y0C3F6IaLdOgSjVnYq!t*w-z1D4G8JbMeQhTkWoZr%u(x+B2E5H9KcOfRiUmXp#sv)z0C3F7IaLdPgSjVnYq$t*w-A1D4G8JbNeQhTlWoZr%u(y+B2E6H9KcOfRjUmXp!sv)z0C4F7IaMdPgSkVnZq$t*x-A1D5G8KbNeQiTlWo#r%v(y+B3E6H9LcOfRjUmYp!sw)z0C4F7JaMdPhSkVnZq$u*x-A2D5G8KbNfQiTlXo#r%v(y0B3E6I9LcOgRjVmYp!tw)z1C4G7JaMePhSkWnZq$u*x+A2D5H8KbNfQiUlXo#s%v(y0B3F6I9LdOgRjVmYq!tw-z1C4G7JbMePhTkWnZr$u(x+A2E5H8KcNfRi