This text is a complete introduction to research methods in political science, covering all the topics typically included in a one semester undergraduate-level course. It concentrates on the basics of what a student needs to know how to do to be an effective consumer of scientific research and begin to conduct his or her own research projects. The approach of “learning by doing” is encouraged through numerous examples and exercises. The book is written in an informal style, with minimal use of technical jargon.

by same inethod such as flipping a coin, Xf this is done, then the two groups should, statisticalljf, be identical in their distribution on not only the depende~itvariable but. also on any otlzes variables, wllether or not those variables can be measured. Sornetimes randomization is not used, mainly because the number of 34 Research I>wign subjects in the experiment is too small, Under those circumstances it is necessary to use a pretest to rneasure the dependent variable. Then a procedure

x~atior~s in these (and most other sources) is compiled from reports submitted by the governments of those nations. Therehre, it is always possible that there are considerable irraccuracies in solBe of the data, whether by design or by accident, A number of other international agencies publish statistics on naic The International Monetar). tions, particularly e c o n o ~ ~indicators. Fund (IMF) publishes the lnterniational Financial Sli;ltistics Yearbook. The Wc~rlciBank publishes the World

even fewer c m be quite useful for many research yurposes. One factor that makes little difference is the size of the population from which the sarnple i s drawn. It i s true that a saiinpie of any given size taken from a single city wifL be more accurate than one drawn from the whole world, bm unless the sample size is one half or more of the population size, the gain in accriracp is very small. Sampling can he dune in several different ways. A simple or pure rundvm siznzpk i s a sample taken by

as possible, avoiding the use of crosshatcfning. Although unnecessary wordirlg within a graphic sho~zld be avoided, some use of words is essential to any chart or graph. Witlain the graphic, it is essential that the variables be clearly Xabeled, including the uilits in which they are measured. Every graphic should have a titfe above it specifying what the graph is, again including the variables. Finaily, if the data are nut generated from the research you are presenting but are from another

of the control variable, a table is constructed sl-rowing tlte relationship between the independent and dependent variables, Each of these tables may then he presented in terms of percentages and appropriate statistics may be calculated. Note that to evaluate the effect of the control variable, it is Ilecessary to compare the contrt>l tables to a table without a control variabie, Box 10.1 illustrates this procedure for a simple case i r ~which all variables are dichotoxnized. Suppose we wanted