This was the also the conclusion of Leslie Olsen and Rod Johnson (1989), who wrote: "In their study, Duffy and Kabance were trying to directly manipulate the understanding of the words and the syntax of the sentences. However, it seemed to us that they were also unintentionally altering other aspects of the text - in particular, the cohesive structures of the text."

In their paper, Olsen and Johnson defined "sensed cohesion" as the strength of the textual topicality and the sense of givenness. The strength of textual topicality is related to the persistence of what the text is about. The sense of givenness is the recognition that the reader has seen a particular noun phrase before.

In analyzing the passages of the Duffy and Kabance study, Olsen and Johnson found that long sentences were broken up into short sentences. In the process, they introduced new subjects. The original focus on the Spaniards was lost, making it difficult to know what the text is about. They analyzed the cohesiveness of the text and concluded, "the intended and the unintended effects of the revisions cancelled one another out," bringing the results of the study into question.

Original (11th Grade)
The night was cloudy, and a drizzling rain, which fell without intermission, added to the obscurity. Steadily, and as noiselessly as possible, the Spaniards made their way along the main street, which had so lately resounded to the tumult of battle. All was now hushed in silence; they were only reminded of the past by the occasional presence of some solitary corpse, or a dark heap of the slain, which too plainly told where the strife had been the hottest. As they passed along the lanes and alleys which opened into the great street, they easily fancied they discerned the shadowy forms of their foe lurking in ambush, ready to spring upon them. But it was only fancy; they city slept undisturbed even by the prolonged echoes of the tramp of the horses, and the hoarse rumbling of the artillery and baggage trains. At length, a lighter space beyond the dusky line of buildings showed the van of the army that it was emerging on an open causeway. They might well have congratulated themselves on having thus escaped the dangers of an assault in the city itself, and that a brief time would place them in comparative safety on the opposite shore.
Sentences and Vocabulary Revised (5th Grade)
The night was cloudy. A sprinkling rain added to the darkness. It fell without a break. The Spaniards made their way along the main street. They moved without stopping and with as little noise as possible. The street had so recently roared to the noise of battle. All was now hushed in silence. The presence of a single dead body reminded them of the past. A dark heap of the slain also reminded them. Clearly, the battle had been worse there. They passed along the lanes and alleys opening into the great street. They easily fancied the shadows of their enemy lying in wait. The enemy looked ready to spring upon them. But it was only fancy. The city slept without being bothered by the rough rumbling of the cannons and baggage trains. Even the constant sound of the tramp of horses did not bother the city. At length, there was a bright space beyond the dark line of the buildings. This informed the army look-out of their coming out onto the open highway. They might well have rejoiced. They had thus escaped the dangers of an attack in the city itself. A brief time would place them in greater safety on the opposite shore.
Fig. 9. Original and revised samples of the passages used in the Duffy and Kabance study of 1981. Lack of attention to coherence and other important variables can cancel out the effects of rewriting the text using the readability-formula variables.

The Charrow and Charrow study Critics of the formulas (e.g., Bruce et al. 1981, Redish and Selzer; Redish 2000) also refer to the elaborate study of oral jury instructions by attorney Robert Charrow and linguist Veda Charrow (1979). They claimed that simplifying text did not make verbal instructions more comprehensible.

The authors did not use the readability variables in re-writing jury instructions but simplified the instructions using a list of common legal "linguistic constructions." These were: nominalizations, unusual prepositional phrases, misplaced phrases, whiz deletions (use of participles instead of verbs), deletions of "that" or "which" beginning dependent clauses, technical legal terms, imperative terms, negatives, passive voice, word lists, organization, and dependent clauses.