ll are made of the same
material," etc. Fortunately, in most of these cases an additional
question is sufficient to determine whether the subject has in mind a
real similarity. Questions suitable for this purpose are: "Explain what
you mean," "In what respect are they all useful?" "What material do
you mean?" etc. Of course it is only permissible to make use of
supplementary questions of this kind when they are necessary in order to
clarify a response which has already been made.

While the amateur examiner is likely to have more or less trouble in
deciding upon scores, this difficulty rapidly disappears with
experience. The following samples of satisfactory and unsatisfactory
responses will serve as a fairly adequate guide in dealing with doubtful
cases:--

(a) _Snake_, _cow_, _sparrow_

_Satisfactory._ "All are animals" (or creatures, etc.). "All
live on the land." "All have blood" (or flesh, bones, eyes,
skin, etc.). "All move about." "All breathe air." "All are
useful" (_plus_ only if subject can give a use which they have
in common). "All have a little intelligence" (or sense,
instinct, etc.).

_Unsatisfactory._ "All have legs." "All are dangerous." "All
feed on grain" (or grass, etc.). "All are much afraid of man."
"All frighten you." "All are warm-blooded." "All get about the
same way." "All walk on the ground." "All can bite." "All
holler." "All drink water." "A snake crawls, a cow walks, and a
sparrow flies" (or some other difference). "They are not alike."

(b) _Book_, _teacher_, _newspaper_

_Satisfactory._ "All teach." "You learn from all." "All give you
information." "All help you get an education." "All are your
good friends" (_plus_ if subject can explain how). "All are
useful" (_plus_ if subject can explain how).

_Unsatisfactory._ "All tell you the news." "A teacher writes,
and a book and newspaper have writing." "They are not alike."
"All read." "All use the alphabet."

(c) _Wool_, _cotton_, _leather_

_Satisfactory._ "All used for clothing." "We wear them all."
"All grow" (_plus_ if subject can explain). "All have to be sent
to the factory to be made into things." "All are useful" (_plus_
if subject can give a use which all have in common). "All are
valuable" (_plus_ if explained).

_Unsatisfactory._ "All come from plants." "All grow on animals."
"All came off the top of something." "A