diff --git a/lib/Math/Function/Interpolator.pm b/lib/Math/Function/Interpolator.pm
index 9d9b22f..a5a1cf5 100644
--- a/lib/Math/Function/Interpolator.pm
+++ b/lib/Math/Function/Interpolator.pm
@@ -37,6 +37,13 @@ has points => (
     required => 1,
 );
 
+=head1 SUBROUTINES/METHODS
+
+=head2 buildargs
+BUILDARGS
+
+=cut
+
 sub BUILDARGS {    ## no critic (Subroutines::RequireArgUnpacking)
     my $self = shift;
     my %args = ref( $_[0] ) ? %{ $_[0] } : @_;
diff --git a/lib/Math/Function/Interpolator/Cubic.pm b/lib/Math/Function/Interpolator/Cubic.pm
index a20d863..83829bb 100644
--- a/lib/Math/Function/Interpolator/Cubic.pm
+++ b/lib/Math/Function/Interpolator/Cubic.pm
@@ -92,6 +92,13 @@ sub _extrapolate_spline {
     return $first->{y} - ( $first->{x} - $x ) * $derivative1;
 }
 
+=head1 SUBROUTINES/METHODS
+
+=head2 cubic
+do_calculation
+
+=cut
+
 # Returns the interpolated_y given point_x and a minimum of 5 data points
 sub do_calculation {
     my ( $self, $x ) = @_;
diff --git a/lib/Math/Function/Interpolator/Linear.pm b/lib/Math/Function/Interpolator/Linear.pm
index ae39fc8..fab8822 100644
--- a/lib/Math/Function/Interpolator/Linear.pm
+++ b/lib/Math/Function/Interpolator/Linear.pm
@@ -11,6 +11,10 @@ use Carp qw(confess);
 use Number::Closest::XS qw(find_closest_numbers_around);
 use Scalar::Util qw(looks_like_number);
 
+=head1 NAME
+Math::Function::Interpolator::Linear - Interpolation made easy
+=cut
+
 has 'interpolate' => (
     is       => 'ro',
     isa      => sub {
@@ -20,6 +24,13 @@ has 'interpolate' => (
     required => 1
 );
 
+=head1 SUBROUTINES/METHODS
+
+=head2 linear
+do_calculation
+
+=cut
+
 # Solves for point_y linearly given point_x and an array of points.
 sub do_calculation {
     my ( $self, $x ) = @_;
diff --git a/lib/Math/Function/Interpolator/Quadratic.pm b/lib/Math/Function/Interpolator/Quadratic.pm
index e62a2d5..9a05981 100644
--- a/lib/Math/Function/Interpolator/Quadratic.pm
+++ b/lib/Math/Function/Interpolator/Quadratic.pm
@@ -26,6 +26,13 @@ has 'interpolate' => (
     required => 1
 );
 
+=head1 SUBROUTINES/METHODS
+
+=head2 quadratic
+do_calculation
+
+=cut
+
 # Returns the interpolated_y value given point_x with 3 data points
 sub do_calculation {
     my ( $self, $x ) = @_;