# What is a paired observation or paired variable?

The question kind of asks itself, can anyone explain what a paired observation or paired variable is in basic terms?

My data consist of the number of words learnt in a week for 19 different participants, the data show each subjects age and the number of words learn individually, would this therefore be considered a paired observation?

Thanks for any help!

• While $(\text{age}_i,\text{words}_i)$ would constitute a pair of values associated with participant $i$, those wouldn't normally be regarded as paired data. The term would normally be reserved for cases where you'd be interested in changes from the first member of the pair to the second (so they'd be measured in the same units, for starters). [Often you'd be interested specifically interested in within-pair differences.] – Glen_b -Reinstate Monica Apr 25 '15 at 9:07