diff --git a/fragment_test.go b/fragment_test.go
index 6b6294d76..5c5f03b16 100644
--- a/fragment_test.go
+++ b/fragment_test.go
@@ -448,28 +448,28 @@ func TestFragment_FieldRange(t *testing.T) {
 			t.Fatal(err)
 		}
 
-		// Query for fields greater than (ending with unset column).
+		// Query for fields greater than (ending with unset bit).
 		if b, err := f.FieldRange(pql.GT, bitDepth, 300); err != nil {
 			t.Fatal(err)
 		} else if !reflect.DeepEqual(b.Columns(), []uint64{1000, 3000, 4000}) {
 			t.Fatalf("unexpected columns: %+v", b.Columns())
 		}
 
-		// Query for fields greater than (ending with set column).
+		// Query for fields greater than (ending with set bit).
 		if b, err := f.FieldRange(pql.GT, bitDepth, 301); err != nil {
 			t.Fatal(err)
 		} else if !reflect.DeepEqual(b.Columns(), []uint64{1000, 3000}) {
 			t.Fatalf("unexpected columns: %+v", b.Columns())
 		}
 
-		// Query for fields greater than or equal to (ending with unset column).
+		// Query for fields greater than or equal to (ending with unset bit).
 		if b, err := f.FieldRange(pql.GTE, bitDepth, 300); err != nil {
 			t.Fatal(err)
 		} else if !reflect.DeepEqual(b.Columns(), []uint64{1000, 2000, 3000, 4000}) {
 			t.Fatalf("unexpected columns: %+v", b.Columns())
 		}
 
-		// Query for fields greater than or equal to (ending with set column).
+		// Query for fields greater than or equal to (ending with set bit).
 		if b, err := f.FieldRange(pql.GTE, bitDepth, 301); err != nil {
 			t.Fatal(err)
 		} else if !reflect.DeepEqual(b.Columns(), []uint64{1000, 3000, 4000}) {
@@ -838,7 +838,7 @@ func TestFragment_Blocks(t *testing.T) {
 	// Retrieve initial checksum.
 	var prev []pilosa.FragmentBlock
 
-	// Set first column.
+	// Set first bit.
 	if _, err := f.SetBit(0, 0); err != nil {
 		t.Fatal(err)
 	}
@@ -976,7 +976,7 @@ func TestFragment_WriteTo_ReadFrom(t *testing.T) {
 	f0 := test.MustOpenFragment("i", "f", pilosa.ViewStandard, 0, "")
 	defer f0.Close()
 
-	// Set and then clear columns on the fragment.
+	// Set and then clear bits on the fragment.
 	if _, err := f0.SetBit(1000, 1); err != nil {
 		t.Fatal(err)
 	} else if _, err := f0.SetBit(1000, 2); err != nil {
diff --git a/holder.go b/holder.go
index 1d6b4f461..a80ba4539 100644
--- a/holder.go
+++ b/holder.go
@@ -466,7 +466,7 @@ func (h *Holder) flushCaches() {
 // RecalculateCaches recalculates caches on every index in the holder. This is
 // probably not practical to call in real-world workloads, but makes writing
 // integration tests much eaiser, since one doesn't have to wait 10 seconds
-// after setting columns to get expected response.
+// after setting bits to get expected response.
 func (h *Holder) RecalculateCaches() {
 	for _, index := range h.Indexes() {
 		index.RecalculateCaches()
diff --git a/holder_test.go b/holder_test.go
index c5b2ad76d..c7877e3ba 100644
--- a/holder_test.go
+++ b/holder_test.go
@@ -330,7 +330,7 @@ func TestHolder_DeleteIndex(t *testing.T) {
 	hldr := test.MustOpenHolder()
 	defer hldr.Close()
 
-	// Write columns to separate indexes.
+	// Write bits to separate indexes.
 	f0 := hldr.MustCreateFragmentIfNotExists("i0", "f", pilosa.ViewStandard, 0)
 	if _, err := f0.SetBit(100, 200); err != nil {
 		t.Fatal(err)
diff --git a/row.go b/row.go
index 61e735626..ec2c42726 100644
--- a/row.go
+++ b/row.go
@@ -22,7 +22,8 @@ import (
 	"github.com/pilosa/pilosa/roaring"
 )
 
-// Row represents a set of columns.
+// Row is a set of integers (the associated columns), and attributes which are
+// arbitrary key/value pairs storing metadata about what the row represents.
 type Row struct {
 	segments []RowSegment
 
@@ -115,7 +116,7 @@ func (r *Row) Xor(other *Row) *Row {
 	return &Row{segments: segments}
 }
 
-// Union returns the columnwise union of r and other.
+// Union returns the bitwise union of r and other.
 func (r *Row) Union(other *Row) *Row {
 	var segments []RowSegment
 	itr := newMergeSegmentIterator(r.segments, other.segments)
@@ -226,7 +227,7 @@ func (r *Row) DecrementCount(i uint64) {
 	}
 }
 
-// Count returns the number of set columns in the row.
+// Count returns the number of columns in the row.
 func (r *Row) Count() uint64 {
 	var n uint64
 	for i := range r.segments {
@@ -238,8 +239,8 @@ func (r *Row) Count() uint64 {
 // MarshalJSON returns a JSON-encoded byte slice of r.
 func (r *Row) MarshalJSON() ([]byte, error) {
 	var o struct {
-		Attrs map[string]interface{} `json:"attrs"`
-		Columns  []uint64               `json:"columns"`
+		Attrs   map[string]interface{} `json:"attrs"`
+		Columns []uint64               `json:"columns"`
 	}
 	o.Columns = r.Columns()
 
@@ -267,8 +268,8 @@ func encodeRow(r *Row) *internal.Row {
 	}
 
 	return &internal.Row{
-		Columns:  r.Columns(),
-		Attrs: encodeAttrs(r.Attrs),
+		Columns: r.Columns(),
+		Attrs:   encodeAttrs(r.Attrs),
 	}
 }
 
@@ -339,7 +340,7 @@ func (s *RowSegment) Intersect(other *RowSegment) *RowSegment {
 	}
 }
 
-// Union returns the columnwise union of s and other.
+// Union returns the bitwise union of s and other.
 func (s *RowSegment) Union(other *RowSegment) *RowSegment {
 	data := s.data.Union(&other.data)