diff --git a/src/observation/ordinal.rs b/src/observation/ordinal.rs
index 289f049..9301397 100644
--- a/src/observation/ordinal.rs
+++ b/src/observation/ordinal.rs
@@ -56,20 +56,18 @@ fn cvi_expectations<F>(mean: f64, var: f64, ll_fct: F) -> (f64, f64, f64)
 where
     F: Fn(f64) -> f64,
 {
-    const N: usize = 30;
-
     let std = var.sqrt();
+
     let mut exp_ll = 0.0;
     let mut alpha = 0.0;
     let mut beta = 0.0;
 
-    for i in 0..N {
-        let val =
-            (ROOTS_HERMITENORM_WS[i] / TAU.sqrt()) * ll_fct(std * ROOTS_HERMITENORM_XS[i] + mean);
+    for (ws, xs) in ROOTS_HERMITENORM_WS.iter().zip(ROOTS_HERMITENORM_XS.iter()) {
+        let val = (ws / TAU.sqrt()) * ll_fct(std * xs + mean);
 
         exp_ll += val;
-        alpha += (ROOTS_HERMITENORM_XS[i] / std) * val;
-        beta += ((ROOTS_HERMITENORM_XS[i].powi(2) - 1.0) / (2.0 * var)) * val;
+        alpha += (xs / std) * val;
+        beta += ((xs.powi(2) - 1.0) / (2.0 * var)) * val;
     }
 
     (exp_ll, alpha, beta)