I am trying to use a "match" function and I keep getting the same error "Unknown or uninitialised column". I am not sure what is happening or why I keep getting this error. I have tried some setting changing (as suggested by the other online help forums) and nothing has helped.

```
Practice_performance_measures <- read_csv("~/Practice_performance_measures.csv",
+ na = "NA")
View(Practice_performance_measures)
Practice_EM <- read_csv("~/Practice_EM.csv",
+ na = "NA")
View(Practice_EM)
diagnostics supress =Practice_performance_measures$AveragePerf
AveragePerf <- Practice_performance_measures$`Average Perf`
Average <- Practice_performance_measures$`Average Perf`
summary(AveragePerf)
Practice_EM$Peformance <- Practice_performance_measures$Average[match(Practice_EM$Participant, Practice_performance_measures$Participant)]
```