Description Author(s) References See Also Examples

Provides tools for the stochastic simulation of effectiveness scores to mitigate data-related limitations of Information Retrieval evaluation research. These tools include:

Fitting of continuous and discrete distributions to model system effectiveness.

Plotting of effectiveness distributions.

Selection of distributions best fitting to given data.

Transformation of distributions towards a prespecified expected value.

Proxy to fitting of copula models based on these distributions.

Simulation of new evaluation data from these distributions and copula models.

**Maintainer**: Julián Urbano [email protected]

Other contributors:

Thomas Nagler [email protected] [contributor]

J. Urbano and T. Nagler. (2018). Stochastic Simulation of Test Collections: Evaluation Scores. ACM SIGIR.

Useful links:

Report bugs at https://github.com/julian-urbano/simIReff/issues

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 | ```
## Fit a marginal AP distribution and simulate new data
x <- web2010ap[,10] # sample AP scores of a system
e <- effContFitAndSelect(x, method = "BIC") # fit and select based on log-likelihood
plot(e) # plot pdf, cdf and quantile function
e$mean # expected value
y <- reff(50, e) # simulation of 50 new topics
## Transform the distribution to have a pre-specified expected value
e2 <- effTransform(e, mean = .14) # transform for expected value of .14
plot(e2)
e2$mean # check the result
## Build a copula model of two systems
d <- web2010ap[,2:3] # sample AP scores
e1 <- effCont_norm(d[,1]) # force the first margin to follow a truncated gaussian
e2 <- effCont_bks(d[,2]) # force the second margin to follow a beta kernel-smoothed
cop <- effcopFit(d, list(e1, e2)) # copula
y <- reffcop(1000, cop) # simulation of 1000 new topics
c(e1$mean, e2$mean) # expected means
colMeans(y) # observed means
## Modify the model to both systems have the same distribution
cop2 <- cop # copy the model
cop2$margins[[2]] <- e1 # modify 2nd margin
y <- reffcop(1000, cop2) # simulation of 1000 new topics
colMeans(y) # observed means
## Automatically build a gaussian copula to many systems
d <- web2010p20[,1:20] # sample [email protected] data from 20 systems
effs <- effDiscFitAndSelect(d, support("p20")) # fit and select margins
cop <- effcopFit(d, effs, family_set = "gaussian") # fit copula
y <- reffcop(1000, cop) # simulate new 1000 topics
# compare observed vs. expected mean
E <- sapply(effs, function(e) e$mean)
E.hat <- colMeans(y)
plot(E, E.hat)
abline(0:1)
# compare observed vs. expected variance
Var <- sapply(effs, function(e) e$var)
Var.hat <- apply(y, 2, var)
plot(Var, Var.hat)
abline(0:1)
# compare distributions
o <- order(colMeans(d))
boxplot(d[,o])
points(colMeans(d)[o], col = "red", pch = 4) # plot means
boxplot(y[,o])
points(colMeans(y)[o], col = "red", pch = 4) # plot means
``` |

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