- table
- Organizational device in which information is summarized and
organized.

- table of random numbers
- A table containing a long list of randomly generated
numbers. Such tables are used for random selection and
assignment of participants.

- target population
- Population to which we hope to generalize the findings of a
research study. The researcher rarely has access to more than a
portion of the target population.

- taxometric search procedures
- A set of mathematical procedures that seeks to identify
taxonic categories. If the sample includes individuals from more
than one taxon, predictable mathematical relationships should
exist between traits, and these mathematical relationships
should be different from those expected if there are no
underlying taxonic categories.

- taxon
- A subgroup that is different in kind and not just degree
from other subgroups. For example, males and females represent
different taxa (plural of taxon) because they are genetically
different from each other.

- technology
- Physical instruments or tools used by researchers.
Technology does not define science; it merely provides tools for
scientists.

- tenacity
- Way of knowing based on accepting an idea as true because it
has been accepted as true for a long time.

- testing
- Potential confounding variable in research that represents
any change in a participant's score on a dependent measure due
to the participant having been tested previously.

- test-retest reliability
- Index of the consistency in scores over time. Test-retest
reliability is computed by calculating the Pearson
product-moment correlation between scores from two testings
separated by some specified time interval.

- theology
- The philosophical tenets and/or study of religion.

- theoretical concept
- Abstraction (thought or idea) that defines the relationship
between two or more variables.

- theory
- The collection of ideas about how and why variables are
related to one another. It is usually built on empirical
observations and is validated by making predictions deduced from
the theory, which are then empirically tested.

- time-series design
- See
*interrupted time-series design*.

- title page
- The first page of a research report manuscript that lists
the authors and their affiliations, the title of the paper, and
a running head (a brief title which will appear at the top of
each page in the published paper).

- treatment
- See
*manipulation*.

- trimodal
- A distribution that has three
*modes*.

- true experiment
- See
*experiment*.

- true zero
- Characteristic of a measurement scale in which zero
represents a zero amount of the concept being measured.

*t*-test- Statistical procedure designed to test for mean differences
between two groups of participants.

*t*-test for independent groups- Statistical procedure designed to test for mean differences
between two groups of participants in which all participants in
the study appear in one and only one group.

- two-group, posttest-only design
- A design in which two groups of participants are compared
after some manipulation of the independent variable.

- two-way ANOVA
- Statistical procedure for the analysis of a factorial design
with two independent variables.

- Type I error
- Probability of rejecting the
*null hypothesis*when the null hypothesis is true.

- Type II error
- Probability of not rejecting the
*null hypothesis*when the null hypothesis is false.