diff --git a/ars.lua b/ars.lua
index 03ac486..ef4df1a 100644
--- a/ars.lua
+++ b/ars.lua
@@ -64,7 +64,7 @@ function Ars:init(dims, popsize, poptop, base_rate, sigma, antithetic)
     self.dims = dims
     self.popsize = popsize or 4 + (3 * floor(log(dims)))
     base_rate = base_rate or 3/5 * (3 + log(dims)) / (dims * sqrt(dims))
-    self.weight_rate = base_rate
+    self.param_rate = base_rate
     self.sigma_rate = base_rate
     self.covar_rate = base_rate
     self.sigma = sigma or 1
@@ -190,7 +190,7 @@ function Ars:tell(scored, unperturbed_score)
     end
 
     for i, v in ipairs(self._params) do
-        self._params[i] = v + self.weight_rate * step[i]
+        self._params[i] = v + self.param_rate * step[i]
     end
 
     self.noise = nil
diff --git a/config.lua b/config.lua
index 1420019..8173282 100644
--- a/config.lua
+++ b/config.lua
@@ -50,9 +50,9 @@ local common_cfg = {
     min_refresh = 0.1, -- for SNES.
 
     -- epoch-related rates:
-    base_rate = 1.0, -- weight_rate, sigma_rate, and covar_rate will base on this
+    base_rate = 1.0, -- param_rate, sigma_rate, and covar_rate will base on this
                      -- if you don't specify them individually.
-    weight_decay = 0.0,
+    param_decay = 0.0,
     sigma_decay = 0.0, -- for SNES, xNES.
 }
 
@@ -75,9 +75,9 @@ if preset == 'snes' then
         deviation = 1.0,
         min_refresh = 0.2,
 
-        weight_rate = 0.5,
+        param_rate = 0.5,
         sigma_rate = 0.1,
-        weight_decay = 0.02, -- note: multiplied by its std, and weight_rate.
+        param_decay = 0.02, -- note: multiplied by its std, and param_rate.
         sigma_decay = 0.01, -- note: multiplied by sigma_rate.
     }
 
@@ -108,9 +108,9 @@ elseif preset == 'snes2' then
 
         epoch_trials = 100,
 
-        weight_rate = 1.0,
+        param_rate = 1.0,
         sigma_rate = 0.01,
-        weight_decay = 0.02,
+        param_decay = 0.02,
         sigma_decay = 0.01,
     }
 
@@ -140,7 +140,7 @@ elseif preset == 'xnes' then
 
         epoch_trials = 50,
 
-        weight_rate = 1.0,
+        param_rate = 1.0,
         sigma_rate = 0.01,
         covar_rate = 0.01,
     }
@@ -171,10 +171,10 @@ elseif preset == 'xnes2' then
 
         epoch_trials = 10, --50,
 
-        weight_rate = 0.5,
+        param_rate = 0.5,
         sigma_rate = 0.04,
         covar_rate = 0.04,
-        weight_decay = 0.004,
+        param_decay = 0.004,
         sigma_decay = 0.00128,
     }
 
@@ -202,8 +202,8 @@ elseif preset == 'ars' then
 
         epoch_trials = 25 * 2,
 
-        weight_rate = 1.0,
-        weight_decay = 0.0025,
+        param_rate = 1.0,
+        param_decay = 0.0025,
     }
 
 elseif preset == 'play' then
@@ -224,9 +224,9 @@ end
 setmetatable(cfg, {__index=common_cfg}) -- gets overridden later.
 
 if cfg.es == 'ars' then
-    if cfg.weight_rate == nil then cfg.weight_rate = cfg.base_rate end
+    if cfg.param_rate == nil then cfg.param_rate = cfg.base_rate end
 else
-    if cfg.weight_rate == nil then cfg.weight_rate = 1.0 end
+    if cfg.param_rate == nil then cfg.param_rate = 1.0 end
 end
 if cfg.sigma_rate == nil then cfg.sigma_rate = cfg.base_rate end
 if cfg.covar_rate == nil then cfg.covar_rate = cfg.sigma_rate end
diff --git a/main.lua b/main.lua
index c554d06..7a1b105 100644
--- a/main.lua
+++ b/main.lua
@@ -283,24 +283,24 @@ local function learn_from_epoch()
                 es.std[i] = v * (1 - es.sigma_rate * cfg.sigma_decay)
             end
         end
-        if cfg.weight_decay > 0 then
+        if cfg.param_decay > 0 then
             for i, v in ipairs(base_params) do
-                base_params[i] = v * (1 - es.weight_rate * cfg.weight_decay * es.std[i])
+                base_params[i] = v * (1 - es.param_rate * cfg.param_decay * es.std[i])
             end
         end
     elseif cfg.es == 'xnes' then
         if cfg.sigma_decay > 0 then
             es.sigma = es.sigma * (1 - cfg.sigma_decay)
         end
-        if cfg.weight_decay > 0 then
+        if cfg.param_decay > 0 then
             for i, v in ipairs(base_params) do
-                base_params[i] = v * (1 - es.weight_rate * cfg.weight_decay)
+                base_params[i] = v * (1 - es.param_rate * cfg.param_decay)
             end
         end
     else
-        if cfg.weight_decay > 0 then
+        if cfg.param_decay > 0 then
             for i, v in ipairs(base_params) do
-                base_params[i] = v * (1 - cfg.weight_decay)
+                base_params[i] = v * (1 - cfg.param_decay)
             end
         end
     end
@@ -309,7 +309,7 @@ local function learn_from_epoch()
 
     local trial_mean, trial_std = calc_mean_dev(trial_rewards)
     local delta_mean, delta_std = calc_mean_dev(delta_rewards)
-    local weight_mean, weight_std = calc_mean_dev(base_params)
+    local param_mean, param_std = calc_mean_dev(base_params)
 
     log_csv{
         epoch = epoch_i,
@@ -318,8 +318,8 @@ local function learn_from_epoch()
         delta_mean = delta_mean,
         delta_std = delta_std,
         step_std = step_dev,
-        weight_mean = weight_mean,
-        weight_std = weight_std,
+        weight_mean = param_mean,
+        weight_std = param_std,
         test_trial = current_cost or 0,
         decisions = decisions_made,
     }
@@ -335,7 +335,7 @@ local function learn_from_epoch()
         end
 
     else
-        print("note: not updating weights in playable mode.")
+        print("note: not updating params in playable mode.")
     end
 
     print()
@@ -516,7 +516,7 @@ local function init()
         error("Unknown evolution strategy specified: " + tostring(cfg.es))
     end
 
-    es.weight_rate = cfg.weight_rate
+    es.param_rate = cfg.param_rate
     es.sigma_rate = cfg.sigma_rate
     es.covar_rate = cfg.covar_rate
     es.rate_init = cfg.sigma_rate -- just for SNES?
diff --git a/snes.lua b/snes.lua
index 164f6f6..282264a 100644
--- a/snes.lua
+++ b/snes.lua
@@ -37,7 +37,7 @@ function Snes:init(dims, popsize, base_rate, sigma, antithetic)
     self.dims = dims
     self.popsize = popsize or 4 + (3 * floor(log(dims)))
     base_rate = base_rate or 3/5 * (3 + log(dims)) / (dims * sqrt(dims))
-    self.weight_rate = 1.0
+    self.param_rate = 1.0
     self.sigma_rate = base_rate
     self.covar_rate = base_rate
     self.sigma = sigma or 1
@@ -251,7 +251,7 @@ function Snes:tell(scored)
     end
 
     for i, v in ipairs(self.mean) do
-        self.mean[i] = v + self.weight_rate * step[i]
+        self.mean[i] = v + self.param_rate * step[i]
     end
 
     local otherwise = {}
diff --git a/xnes.lua b/xnes.lua
index 2be4c14..241a98d 100644
--- a/xnes.lua
+++ b/xnes.lua
@@ -56,7 +56,7 @@ function Xnes:init(dims, popsize, base_rate, sigma, antithetic)
     self.dims = dims
     self.popsize = popsize or 4 + (3 * floor(log(dims)))
     base_rate = base_rate or 3/5 * (3 + log(dims)) / (dims * sqrt(dims))
-    self.weight_rate = 1.0
+    self.param_rate = 1.0
     self.sigma_rate = base_rate
     self.covar_rate = base_rate
     self.sigma = sigma or 1
@@ -183,7 +183,7 @@ function Xnes:tell(scored, noise)
     end
 
     for i, v in ipairs(self.mean) do
-        self.mean[i] = v + self.weight_rate * step[i]
+        self.mean[i] = v + self.param_rate * step[i]
     end
 
     self.sigma = self.sigma * exp(self.sigma_rate * 0.5 * g_sigma)