diff --git a/src/05-derivatives/05-diffusion-derivatives.md b/src/05-derivatives/05-diffusion-derivatives.md
index 0b4b0427..9a2836e3 100644
--- a/src/05-derivatives/05-diffusion-derivatives.md
+++ b/src/05-derivatives/05-diffusion-derivatives.md
@@ -37,11 +37,12 @@ biological structure. A wide range of such models are available, each of
which has its own unique requirements with respect to:
- The [input](#paramdef-input) parameters required in order to
- define / constrain the model;
+ define / constrain the way in which the model will be fit to the
+ empirical image data;
- The appropriate [data representations](#data-representations) utilised to
- store information parameterised [by](#paramdef-intrinsic) or
- [from](#paramdef-extrinsic) the model onto the filesystem;
+ store information parameterised [by](#paramdef-fit) or
+ [from](#paramdef-derived) the model onto the filesystem;
- The requirements for encapsulation and complete representation of
derived [orientation information](#orientation-specification), which is
@@ -59,7 +60,7 @@ these uses is defined thus:
Value or non-numerical setting that influences the conformation
of the diffusion model to the empirical diffusion-weighted data.
-1. *Model* parameter:
+1. Model *fit* parameter:
Value that is the direct result of fitting the diffusion model to the
empirical diffusion-weighted data.
@@ -72,7 +73,7 @@ these uses is defined thus:
For example, consider a diffusion tensor model fit: the number of
iterations in the optimisation algorithm would be an *input* parameter;
-the six unique diffusion tensor coefficients would be the *model*
+the six unique diffusion tensor coefficients would be the *model fit*
parameters; the Fractional Anisotropy (FA) would be a *model-derived*
parameter (as it is calculated from the diffusion tensor coefficients
rather than the image data).
@@ -96,9 +97,9 @@ rather than the image data).
```
- Files "`[_space-]_model-