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TOEFL Directory > TOEFL writing > 43.Statistics
43.Statistics
There were two widely divergent influences on the early development of
statistical methods. Statistics had a mother who was dedicated to
keeping orderly records of government units (states and statistics come
from the same Latin root status) and a gentlemanly gambling father who
relied on mathematics to increase his skill at playing the odds in games
of chance. The influence of the mother on the offspring, statistics, is
represented by counting, measuring, describing, tabulating, ordering,
and the taking of censuses-all of which led to modern descriptive
statistics. From the influence of the father came modern inferential
statistics, which is based squarely on theories of probability.
Describing collections involves tabulating, depicting and describing
collections of data. These data may be quantitative such as measures of
height, intelligence or grade level------variables that are
characterized by an underlying continuum---or the data may represent
qualitative variables, such as sex, college major or personality type.
Large masses of data must generally undergo a process of summarization
or reduction before they are comprehensible. Descriptive statistics is a
tool for describing or summarizing or reducing to comprehensible form
the properties of an otherwise unwieldy mass of data.
Inferential statistics is a formalized body of methods for solving
another class of problems that present great of problems
characteristically involves attempts to make predictions using a sample
of observations. For example, a school superintendent wishes to
determine the proportion of children in a large school system who come
to school without breakfast, have been vaccinated for flu, or whatever.
Having a little knowledge of statistics, the superintendent would know
that it is unnecessary and inefficient to question each child: the
proportion for the sample of as few as 100 children. Thus , the purpose
of inferential statistics is to predict or estimate characteristics of a
population from a knowledge of the characteristics of only a sample of
the population.
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