Fix typo

paper.md

@@ -28,7 +28,7 @@ The quantitative analysis of archaeological assemblages can thus be carried out
 # Summary
 `tabula` attempts to provide a convenient and reproducible toolkit for analysis, seriation and visualization of archaeological count data (artifacts, faunal remains, etc.).
 
-The package uses a set of S4 classes for archaeological data matrices that extend the basic `matrix` data type. These new classes represent different special types of matrix: incidence, abundance, co-occurence and (dis)similarity. Methods for a variety of functions applied to objects from these classes provide tools for relative and absolute dating and analysis of (chronological) patterns.
+The package uses a set of S4 classes for archaeological data matrices that extend the basic `matrix` data type. These new classes represent different special types of matrix: incidence, abundance, co-occurrence and (dis)similarity. Methods for a variety of functions applied to objects from these classes provide tools for relative and absolute dating and analysis of (chronological) patterns.
 
 `tabula` includes functions for matrix seriation (`seriate_*`), as well as chronological modeling and dating (`date_*`) of archaeological assemblages and/or objects. Resulting models can be checked for stability and refined with resampling methods (`refine_*`)). Estimated dates can then be displayed as tempo or activity plot [@dye2016] to assess rhythms of the long term. Beyond these, `tabula` provides several tests (`test_*`) and measures of diversity within and between archaeological assemblages: heterogeneity and evenness (Brillouin, Shannon, Simpson, etc.), richness and rarefaction (Chao1, Chao2, ACE, ICE, etc.), turnover and similarity (Brainerd-Robinson, etc.). Finally, the package make it easy to visualize count data and statistical thresholds (`plot_*`): rank vs. abundance plots, heatmaps, @ford1962 and @bertin1977 diagrams.