Experimental Psychology: A Manual of Laboratory Practice (Classic Reprint) - Tapa blanda

Excerpt from Experimental Psychology: A Manual of Laboratory Practice

I. Measurement - Whenever we measure, in any depart ment of natural science, we compare a given magnitude with some conventional unit of the same kind, and determine how many times the unit is contained in the magnitude. Let P be the magnitude to be measured, and p the unit in terms of which it is to be expressed. The result of our measurement of P is the discovery of the numerical ratio existing between P and p.

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Excerpt from Experimental Psychology: A Manual of Laboratory Practice

On the average, we can still hear a tone of so-and-so many vibrations; on the average, we can distinguish two weights if they differ by such-and-such an amount. The question which the quantitative experiment answers is, therefore, some variant of the question 'How much?' Notice, however, that this is not the question asked of consciousness. That question is always the one or other of the two just mentioned: Present or absent? and Same or different? Here, then, is a second difference between the qualitative and the quantitative experiment. The former, aiming at description, comes to an end when introspection has made its report; the latter, aiming at measurement, subjects the results of introspection to mathematical treatment. The experiments are complementary, each sacrificing something and each gaining something. The qualitative experiment shows us all the detail and variety of the mental life, and in so doing forbids us to pack its results into formulas; the quantitative experiment furnishes us with certain uniformities of the mental life, neatly and summarily expressed, but for that very reason must pass unnoticed many things that a qualitatively directed introspection would bring to light.

The Quantitative Experiment in Practice. - In general, the rules for the conduct of a quantitative experiment are the same as those fora qualitative experiment (vol. I., xiii. f.). There are, however, in practice, certain well-marked differences between the two types of experiment.

(1) In the first place, the quantitative experiment demands much more 'outside' preparatory work than does the qualitative. Most, if not all, of the reading done in preparation for the experiments of vol. I. could be done within the laboratory. This is not the case with the experiments that you are now to perform. The quantitative experiment sums up, in a single representative value, the results of a large number of observations. It is clear, then, that the conditions of observation must be the same throughout: otherwise the results will not be comparable.

About the Publisher

Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com

This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.