I currently work on a draft of an aquatic bioassessment. The conditions tested are the following: ER river water T dechlorinated water control 0.5 + 0.5mg / L of malate T + 1 dechlorinated water control + 1g / L of malate T ED dechlorinated water control SED + ER + river water sediment SED ED + sediment + water dechlorinated. It is the result of AChE in muscle (fillet of fish). The production of acetylcholine is followed with a spectrophotometer every 15 seconds for two minutes. The results are presented in the following table: traitement t15 t30 t45 t60 t75 t90 t105 t120 1 ER 0.100 0.110 0.123 0.135 0.147 0.159 0.171 0.182 2 ER 0.112 0.134 0.153 0.174 0.192 0.208 0.226 0.251 3 T+0.5 0.078 0.082 0.088 0.094 0.101 0.108 0.113 0.120 4 t+0.5 0.053 0.100 0.109 0.120 0.127 0.136 0.145 0.154 5 TED 0.107 0.126 0.141 0.161 0.172 0.184 0.200 0.213 6 TED 0.117 0.135 0.153 0.169 0.183 0.201 0.218 0.229 7 TED 0.124 0.145 0.163 0.187 0.208 0.227 0.244 0.259 8 T+1 0.109 0.119 0.134 0.148 0.163 0.174 0.187 0.202 9 T+1 0.118 0.134 0.153 0.170 0.184 0.197 0.214 0.228 10 SED+ER 0.158 0.175 0.194 0.208 0.226 0.240 0.259 0.268 11 SED+ED 0.119 0.140 0.157 0.174 0.192 0.208 0.225 0.240 12 SED+ED 0.101 0.113 0.180 0.140 0.154 0.166 0.179 0.190 13 SED+ED 0.129 0.135 0.140 0.146 0.153 0.159 0.165 0.172 The statistical test is considered a repeated measures anova but I do not know how to do it in R. I watched the forums and I downloaded the R package 'nlme' by which I should be able to use the function 'lm'. But the problem is that I can not encode this function. Could you help me?