Helper functions for Numbers Needed for Change

These functions are used by nnc() in the behaviorchange package to compute the Numbers Needed for Change, but are also available for manual use.

convert.cer.to.d(
  cer,
  eer,
  eventDesirable = TRUE,
  eventIfHigher = TRUE,
  dist = "norm",
  distArgs = NULL,
  distNS = "stats"
)

convert.d.to.eer(
  d,
  cer,
  eventDesirable = TRUE,
  eventIfHigher = TRUE,
  dist = "norm",
  distArgs = list(),
  distNS = "stats"
)

convert.d.to.nnc(d, cer, r = 1, eventDesirable = TRUE, eventIfHigher = TRUE)

convert.eer.to.d(
  eer,
  cer,
  eventDesirable = TRUE,
  eventIfHigher = TRUE,
  dist = "norm",
  distArgs = NULL,
  distNS = "stats"
)

Arguments

cer

The Control Event Rate.

eer

The Experimental Event Rate.

eventDesirable

Whether an event is desirable or undesirable.

eventIfHigher

Whether scores above or below the threshold are considered 'an event'.

dist, distArgs, distNS

Used to specify the distribution to use to convert between Cohen's d and the CER and EER. distArgs can be used to specify additional arguments to the corresponding q and p functions, and distNS to specify the namespace (i.e. package) from where to get the distribution functions.

d

The value of Cohen's d.

r

The correlation between the determinant and behavior (for mediated Numbers Needed for Change).

Value

The converted value.

References

Gruijters, S. L., & Peters, G. Y. (2019). Gauging the impact of behavior change interventions: A tutorial on the Numbers Needed to Treat. PsyArXiv. doi: 10.31234/osf.io/2bau7

See also

nnc() in the behaviorchange package.

Author

Gjalt-Jorn Peters & Stefan Gruijters

Maintainer: Gjalt-Jorn Peters gjalt-jorn@userfriendlyscience.com

Examples

convert.d.to.eer(d=.5, cer=.25);
#> [1] 0.4307403
convert.d.to.nnc(d=.5, cer=.25);
#> [1] 5.532801
#> attr(,"eer")
#> [1] 0.4307403