About variable, value/level, condition and treatment

In the hope of less confusion, another explanation of the terms variable, value/level, condition and treatment:

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A first independent variable X, can take certain values (verdier?), also called levels (niv?er?): X1, X2, X3, ...

A second independent variable Y, can take certain values (verdier?), also called levels (niv?er?): Y1, Y2, Y3, ...

(for 'levels' see book, p. 56)

The sum of values or levels (here: 3+3) does not interest anyone (other than when you do two basic design studies after each other, one for each independent variable). But the PRODUCT of each number of levels does interest, namely in a FACTORial design, so 3 times 3 possible conditions (villk?r?) arise, which participants of an experiment can experience/go through in different ways. A ¡®condition¡¯ is - in a basic design - the same as a value/level of the one IV, but particularly in a factorial design a condition is a combination of values/levels of the at least 2 IVs. So, X1+Y1, ..., X3+Y3 those 9 possible combinations of the IVs' levels. A ¡®condition¡¯ is then also what you expose your participants to.

Condition is almost the same as treatment (behandling?), just that we usually distinguish between a treatment condition and a control condition - see book page 45. In a treatment condition there happens something extraordinary/or is tested) and in a control condition there usually happens nothing special/or is tested: a kind of non-treatment/placebo-treatment.

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Feel free to address any further questions to either group teachers or course responsibles.