D4.4.9-12: Critiquing Claims and Evidence for Credibility

Overview

Lesson Procedure

75-80 minutes of class time across 5 phases.

1. Warm-Up10 minutes
2. Direct Instruction30 minutes
3. Guided Practice15 minutes
4. Independent Practice10-15 minutes
5. Closure10 minutes

1. Warm-Up10 minutes

   Warm-Up Prompt

   "A team wears new socks and wins three games in a row. The sock company's ad says, 'Our socks win games.' Write down every reason the evidence might not support the claim. Then rewrite the claim so that the evidence does support it."

   Sort students' reasons into two columns on the board. Reasons about the claim (it is too broad, too certain, or not something the company could know) go on the left. Reasons about the evidence (only three games, the team may have improved anyway, the company chose what to report, no comparison with games in old socks) go on the right. These become the two halves of the Claim and Evidence Audit. Tell students that today's arguments are about whether people could make it rain, and that the critics' claims get audited too.

2. Direct Instruction30 minutes

   Part 1: The question and the sources. The compelling question is "How credible were the claims of the 1890s rain-makers, and of their critics?" The debate is a vehicle for the skill. Harrington reports that Senator Farwell obtained appropriations "first of $2,000, then of $7,000" and that the Department of Agriculture chose R. G. Dyrenforth to run the experiments (Source 5, paragraph 1). Dyrenforth's method was concussion: explosions meant to jar clouds into releasing rain. In Sources 1-4, Sanford, a physics professor at Stanford, reads a newspaper report about a California rain-maker to his students in 1894 and then answers it. Harrington wrote for the National Geographic Magazine in 1894, while he was Chief of the U.S. Weather Bureau (its first chief, 1891-1895, according to the National Weather Service); the Weather Bureau was then part of the Department of Agriculture, the department that ran Dyrenforth's tests. He says he "personally urged" Dyrenforth to add a check (Source 5, paragraph 7). Source 8, also from Harrington, quotes a letter by Professor A. Macfarlane of the University of Texas, an "uninvited guest" at the 1892 San Antonio test.

   Source Information: who made each source, when, and from what position (from the sources, their bylines and their notes)

   Source	Maker and position	When	Position
   1: Examiner report	The San Francisco Examiner, as read aloud by Sanford	February 2, 1894	Reports that Frank Baker made rain at Pixley
   2-4: Sanford	Fernando Sanford, Professor of Physics, Leland Stanford Junior University, in a lecture to students	March 1894, printed August 1894	Against all rain-making claims of his day
   5: Harrington	Mark W. Harrington, Chief of the U.S. Weather Bureau, writing in the National Geographic Magazine	1894, reprinted 1896	Skeptical; reports evidence on both sides
   8: Macfarlane via Harrington	A. Macfarlane, University of Texas, an uninvited observer	Letter of December 4, 1892	Skeptical eyewitness of the San Antonio test
   6 and 7	Invented critiques and an invented scenario written for this page	Invented	Practice material; two critiques in Source 6 are deliberately weak

   1HE PRODUCES RAIN AT WILL.
   Highly Successful Experiments of the Visalia Rain-maker.
   HEAVY SHOWERS AT PIXLEY.
   He selects the Driest Section of Fresno County, where Rain seldom falls, and BY the Use of Chemicals causes Local Downpours on Two Successive Days. Many other Tests made.

   2Visalia, February 1st.—A week ago Wednesday Frank Baker, of Visalia, an amateur rain-maker, went to Pixley for the purpose of producing rain. Before he left he informed the Examiner correspondent that he intended to produce rain within seven days, and he kept his word. On Tuesday and Wednesday a local rainstorm occurred in the vicinity of Pixley amounting to 0·35 to 0·45 of an inch.

   [...]

   3During the months of April and May he proposes to put forth his best efforts in order to thoroughly drench the soil. The residents of Pixley are well pleased with Baker's experiments, and they propose to assist him in conducting his future operations.

   4THEY VOUCH FOR HIS EFFICIENCY.
   He brought back with him the following letter:

   5"This is to certify that it rained 0·35 to 0·40 of an inch at Pixley on the 30th and 31st of January. We gentlemen here vouch for the truth of the same; that it is a local rain of fifteen to twenty miles in extent, and that it was brought about by the Baker process.

   6"J. J. Kelly,
   L. E. Smith,
   "Charles S. Peck,
   J. T. Austin,
   "W. M. Jackin,
   John W. Harper."

   1Now, it is not my purpose to impugn the veracity of the gentlemen whose names are signed to this certificate. I know none of the gentlemen. I do not question the only point in the statement to which the gentlemen could possibly subscribe of their own knowledge. You will observe that the certificate includes three separate statements: (1) That it rained in Pixley on the 30th and 31st of January; (2) that it was a local rain of fifteen to twenty miles in extent; (3) that it was brought about by the Baker process. Manifestly, the only one of these statements to which the gentlemen could have subscribed of their own knowledge is the first.

   2Fortunately for the settlement of questions of this character, we have the use of data collected by the Weather Bureau. When I read the above article I at once wrote to Mr. Pague for the maps issued by the Weather Bureau for January 28th to 31st inclusive. He kindly forwarded them to me, and the following data were compiled by me from them:

   3On the map of Sunday, January 28th, 5 P. M., an area of low barometer is shown with its center west of Vancouver. The weather was reported cloudy and rainy north of the Oregon line. The weather forecast was "Rain in northern California." Twelve hours later, Monday, January 29th, at 5 A. M., the storm was central over northwestern Washington. I quote verbatim from the predictions printed upon the map: "The conditions this morning are favorable for rain over California from the Tehachapi Mountains northward by Tuesday morning, and possibly will extend southward Tuesday afternoon or night."

   4At 5 p. m. of the same day the map shows a storm area extending from British Columbia to southeastern California, with its center near Keeler, about ninety miles east of Pixley. Here the storm center remained for thirty-six hours, while the storm was gradually breaking up over its northern part, as shown by the three following maps, and not until the map of Wednesday morning is there an indication of an eastward movement of the storm, while as late as 5 p. m. of Wednesday, January 31st, rain was reported at Keeler. During Monday and Tuesday light rains were reported over nearly all parts of the State, and on Tuesday it rained at Pixley.

   5[...] As a matter of fact, it rained at Pixley on Tuesday night, as had been predicted by Mr. Pague thirty-six hours before.

   1And now as to the possibility of producing rain by artificial means. It is never safe to say what things are possible and what things are impossible to man. What the future may bring forth no one can tell. At the present time, however, there is no evidence to show that even the smallest local shower has been produced artificially. Further than that it is safe to say that no method of producing artificial rain has yet been publicly proposed which suggests to one familiar with the scientific principles involved even a possibility of success. That such attempts have received the official recognition and the financial support of Congress is only another evidence of the gross ignorance of scientific principles which is prevalent among our so-called educated men. That some of the men who advocate these wild schemes are honest in their motives can not be questioned, but that all the professional rain-makers are conscienceless fakirs is scarcely more questionable. That many of them are able to submit testimony as to the efficacy of their system is equally true of every patent-medicine fraud and electric-healing quack who has ever swindled an ignorant public. As an illustration of the value of testimony of this kind let me give you a local example.

   1Dyrenforth.—It is probable that the name of Mr. Dyrenforth is better known in connection with attempts at artificial rain-making than that of any other man. As a result of the agitation of Mr. Powers, Congress voted two thousand dollars to make a preliminary test, and the inquiry fell to the scientists connected with the Department of Agriculture. They reported that there was no foundation for the opinion that days of battle were followed by rain any more than days of no battle. It was then that Mr. Dyrenforth came forward with Ruggles's plans and offered to make some tests. Through the influence of Senator Farwell, an additional appropriation of seven thousand dollars was placed at his disposal for a series of practical tests, which were made at Midland, Texas, in August, 1891. A further Government appropriation was expended in tests at San Antonio, Texas, in November, 1892.

   2Mr. Dyrenforth's plan seems to have been to imitate as nearly as possible the conditions of a battle. His explosives were ranged in a line facing the advancing clouds. Shells were fired into the air at frequent intervals. Dr. Macfarlane states that the "general" and his lieutenant even wore cavalry boots.

   [...]

   3Under these conditions eight balloons, a hundred and fifty shells, and four thousand pounds of rosellite were fired off. No rain appeared. One balloon exploded within a black rain cloud, but failed to produce any precipitation. On the following Wednesday, with a clear sky, ten balloons, a hundred and seventy-five shells, and five thousand pounds of rosellite were exploded, and the sky remained clear. On the following night the remaining stock of explosives were fired off, regardless of consequences, to get rid of them.

   1Senator Farwell, however, continued his interest in the matter, and in 1890 finally succeeded in obtaining an appropriation, first of $2,000, then of $7,000, for carrying on the experiments, some of which he had already had made at his own expense. The appropriation assigned the conduct of the experiments to the Department of Agriculture, and the Secretary selected R. G. Dyrenforth for the work. The experiments were carried on in the vicinity of Washington and in Texas. A report from Mr. Dyrenforth was published by Congress in 1892. At the next session of Congress another appropriation of $10,000 was made for this purpose, of which the sum of $4,913.59 was expended, as before, under Dyrenforth's direction, the remainder having been covered back into the Treasury.

   2Mr. Dyrenforth's methods were highly ingenious. He used a variety of explosives, on the ground and in the air, by great single explosions and by volleys. He introduced many novelties, among them that of exploding the gas in the balloon itself when high in the air. His conclusions, as stated by himself in his first report, were (p. 59):

   3"First. That when a moist cloud is present, which, if undisturbed, would pass away without precipitating its moisture, the jarring of the cloud by concussions will cause the particles of moisture in suspension to agglomerate and fall in greater or less quantity, according to the degree of moistness of the air in and beneath the cloud.

   4"Second. That by taking advantage of those periods which frequently occur in droughts, and in most if not in all sections of the United States where precipitation is insufficient for vegetation, and during which atmospheric conditions favor rainfall, without there being actual rain, precipitation may be caused by concussion.

   5"Third. That under the most unfavorable conditions for precipitation, conditions which need never be taken in operations to produce rain, storm conditions may be generated and rain be induced, there being, however, a wasteful expenditure of both time and material in overcoming unfavorable conditions."

   6His second report has not been published, but I infer that his second series of observations were believed by him to confirm the results of the first.

   7Mr. Dyrenforth generally omitted one check which he might well have employed, and which I personally urged him to employ. Experiments of this sort, made in the free air, with the accompanying conditions not under control, should be accompanied with every possible check; and one self-evident and very necessary one is the observation of a physicist familiar with the meteorologic side of physics. Such an expert (Mr. G. E. Curtis) accompanied the party in its first experiments. His report (except the bare meteorologic record made during the experiments) does not accompany Dyrenforth's document. It was presented, however, to the Philosophical Society of Washington, and was printed elsewhere. Mr. Curtis says, substantially, that an explosion in a cloud brings down a few scattering drops of rain, and this may happen even with an explosion on the ground, if heavy. Otherwise he says there was no rain making. It is but fair to say that with Mr. Dyrenforth's report are given the reports of his assistants, Mr. John T. Ellis, Lieut. S. A. Dyer, and Mr. Eugene Fairchild, and they were stronger in the expression of a belief that rain was successfully made than is Mr. Dyrenforth; and there are also many favorable quotations from spectators.

   1Prof. A. Macfarlane, of the University of Texas, was present as an uninvited guest during the elaborate experiments near San Antonio on Friday, November 25, 1892, beginning at 4 p. m. The sky was from time to time overcast, and the natural conditions were not unfavorable for rain. Many explosions were made without rain until late in the evening, from which point I will take up the story in Professor Macfarlane's own words, as given in a letter to the New York World December 4, 1892:

   2"At 10.15 a balloon was sent up and was lost in the darkness; when it exploded a very large area of light was seen, as if the explosion had occurred inside a cloud. There was no fall of rain at the camp, and nobody was stationed below the spot where the balloon exploded.

   3"I consider this the only experiment that was worth making, yet no care was taken to observe whether rain did fall. It is conceivable that the explosion of a 12-foot balloon inside a cloud ready to precipitate may jar the particles so as to quicken the dropping of the rain. This was the idea of Ruggles. But to test whether some rain can be drawn down in this manner from a rain cloud does not suit the ideas of cranks who wish to get a large something out of an absolute nothing.

   [...]

   4"At 1 o'clock, the time when operations were to be suspended for the night, it was fair, with some stars visible, and the boys were preparing one more balloon. Colonel King remarked that it would be necessary to keep up the operations for forty-eight hours. I retired to a room in the hotel, from which I could see the operations.

   5"At 1.30 I heard a slight shout from the balloon boys, and I could hear the rain pattering on the roof. The General, who had also retired to the hotel, threw open the window and called out: 'Hurry up, boys.' After ten minutes the balloon was exploded, and the rain almost immediately diminished so as to be scarcely perceptible. When the explosion occurred I had my head out of the window. The hotel, a frame house, shook considerably, but there was no breaking of glass or any of the effects produced by a powerful explosion on the solid earth.

   6"At 1.50 the General went out to observe, and I heard him say: 'There is a beautiful rain to the north of us and to the west of us.'

   7"At 2 the rain had entirely ceased, and the last of the operations consisted of two shells fired in succession at 2.05."

   Part 2: Model the audit. Work through the examples aloud with Diagram 1. Terms to define as they come up: precipitation is rain or snow; an "area of low barometer" on a weather map is a low-pressure storm; to "agglomerate" is to clump together; rosellite was an explosive. Point out that the audit has two halves: Examples 1, 3 and 5 test claims, and Examples 2 and 4 test evidence. Example 5 turns the audit on a critic, because a critic's claims need the same tests.

   • Claim: what could the claimant know? (Source 1)

     Six Pixley men certify that "it rained 0·35 to 0·40 of an inch at Pixley on the 30th and 31st of January", that it was "a local rain of fifteen to twenty miles in extent", and "that it was brought about by the Baker process" (Source 1, paragraph 5). Critique the use of these claims.

     Result: The certificate bundles three claims of very different strength. Rain on two days is something the signers could observe. The rain's extent of fifteen to twenty miles is wider than anyone in one town could see. The cause is not observable at all, so their signatures add nothing to it. Sanford makes this split himself (Source 2, paragraph 1). Credible use: cite the certificate for the rain, not for its cause.

   • Evidence: an alternative explanation and its timing (Source 2)

     Baker's evidence is that rain followed his work. Sanford answers with the Weather Bureau's maps and forecasts (Source 2, paragraphs 3-5). How does this change the credibility of Baker's evidence?

     Result: The forecast issued on Monday morning said conditions were "favorable for rain over California from the Tehachapi Mountains northward by Tuesday morning" (paragraph 3), and it rained at Pixley Tuesday night, "as had been predicted by Mr. Pague thirty-six hours before" (paragraph 5). Rain that an independent forecaster expected anyway cannot count as evidence that Baker caused it: rain after an action is not rain because of it. Limitation: Sanford's maps report regional stations; he quotes no gauge reading taken at Pixley itself.

   • Claim: scope and testability (Source 5)

     Dyrenforth's third conclusion says that "under the most unfavorable conditions for precipitation", rain can "be induced", although with "a wasteful expenditure of both time and material" (Source 5, paragraph 5). Critique the claim.

     Result: The claim is as broad as possible (the worst conditions) yet names no amount, place or number of trials, and its built-in excuse (waste) means a failure can always be read as "not enough material yet". A claim that no result could count against is hard to test, so it earns little credibility however confident it sounds. A credible version would state conditions, amount and how success would be measured.

   • Evidence: independence and missing checks (Source 5)

     Harrington says Dyrenforth's report omits the full report of G. E. Curtis, the expert observer, but includes reports from three assistants and "many favorable quotations from spectators" (Source 5, paragraph 7). Critique Dyrenforth's use of evidence and Harrington's.

     Result: Dyrenforth's report keeps the evidence of people on his own team, who were "stronger in the expression of a belief" than he was, and leaves out the independent expert, who says "there was no rain making": a selection problem. Harrington's critique gains credibility by reporting the favorable evidence too ("It is but fair to say"). Its limitation: he gives Curtis's view only "substantially", in his own summary, and he was involved, having "personally urged" a check.

   • Critiquing the critic (Source 3)

     Sanford says that "all the professional rain-makers are conscienceless fakirs is scarcely more questionable" (Source 3). Critique his claim and its evidence.

     Result: His narrower claim, that "there is no evidence to show that even the smallest local shower has been produced artificially", can be tested against the cases he cites. The sweeping claim about "all" rain-makers goes beyond his evidence: he offers "a local example", one case, and the word "fakirs" (frauds) is an insult, not a finding. It also sits oddly beside his own admission that some advocates "are honest in their motives". A credible critic keeps the strong claim and drops the insult.

3. Guided Practice15 minutes

   Pairs read Source 6, four invented critiques. Tell students that two of them are deliberately weak. For each critique, pairs name the audit test it uses, judge whether it is fair to the source, and rewrite the weak ones.

   1These four critiques were written for this page by invented students who read Sources 1-5. Two of them are deliberately weak, so that the class can find what is wrong with them. They are not models.

   2Jonah: "The Pixley certificate is worthless because the six men were probably lying."

   3Priya: "The certificate mixes something the signers saw, rain on two days, with something they could not see, what caused it. Only the first is eyewitness evidence."

   4Tomas: "Dyrenforth's tests must have worked, because Congress paid for them twice."

   5Grace: "Harrington's critique is stronger than Sanford's general verdict, because Harrington names a missing check and also reports the evidence on Dyrenforth's side."

   Teacher key (discussion points). Jonah's critique is weak: it accuses the signers of lying with no evidence, while Sanford himself says "it is not my purpose to impugn the veracity" (truthfulness) of the signers (Source 2, paragraph 1). The real problem is what they could know. Priya's critique is strong: it separates an observation from a cause. Tomas's critique is weak: funding shows that Congress was persuaded, not that rain was made; Harrington reports that of a later $10,000 appropriation only "$4,913.59 was expended" (Source 5, paragraph 1), which says nothing about results either way. Grace's critique is strong: it judges the critics by the same tests.

4. Independent Practice10-15 minutes

   Each student writes one paragraph answering the compelling question. It must audit one claim and one use of evidence from the rain-makers' side and one of each from the critics' side, cite sources by paragraph, and end with an overall judgment that says how credible each side's argument was and why.

5. Closure10 minutes

   Exit ticket: "Name one claim from today that went beyond its evidence, and rewrite it so that it doesn't. Then name one piece of evidence that was strong because of who collected it."

   Teacher note on the sources: Sanford and Macfarlane use insults ("fakirs", "cranks"); treat these as claims to audit, not as evidence. In the 1890s "fakir" was slang for a swindler, borrowed from a word for a Muslim or Hindu religious ascetic; Sanford's use has nothing to do with that religious meaning, and students should not use the word as an insult. The excerpts are about physics and evidence, not about any group of people. Present the rain-makers' supporters fairly: the Examiner calls the Pixley area the "Driest Section of Fresno County", Dyrenforth's own conclusions speak of regions "where precipitation is insufficient for vegetation", and the Pixley report says residents were "well pleased", so their hopes are part of the story.

   Quiz passage. Questions 11-14, 19 and 20 use Source 7, an invented economics scenario.

   1This scenario is invented for this page. The city, the people and all the numbers are invented.

   2The invented city of Riverton held a Friday night market downtown every week in June for the first time. The market's organizers want the city council to pay for it again next year.

   3Source 7A, the organizers' report: "The night market boosted downtown sales by 25%. Every business downtown benefited."

   4Source 7B, the organizers' evidence: four shops that sold goods at the market reported total sales of $48,000 in May and $60,000 in June. The organizers chose the four shops.

   5Source 7C, the city finance office: sales-tax receipts from all downtown businesses were $410,000 in June this year and $386,800 in June last year.

   6Source 7D, a downtown bakery owner: "Market nights took away my customers' parking, so I closed early on Fridays in June."

   7Source 7E, a weather note in the report: May had 9 rainy days and June had 2.

Differentiation Strategies

Assessment Guidance

1. Question 1 of 20 · Multiple Choice

   The Examiner's headline says "HE PRODUCES RAIN AT WILL." (Source 1, paragraph 1). What is the main problem with this claim?

   AIt names the wrong California town for the rain BIt claims far more than one storm could show CIt gives the rainfall in the wrong units DIt was written after Sanford's lecture

2. Question 2 of 20 · Multiple Choice

   The Examiner reports "0·35 to 0·45 of an inch" of rain (Source 1, paragraph 2), while the certificate says "0·35 to 0·40 of an inch" (paragraph 5). What does the difference suggest?

   AThe two accounts were not careful measurements BBaker made two separate storms on two different days CThe certificate was written by the Examiner DThe Weather Bureau had changed the figures

3. Question 3 of 20 · Multiple Choice

   Before going to Pixley, Baker said "he intended to produce rain within seven days, and he kept his word" (Source 1, paragraph 2). Why is this kept promise weak evidence?

   ABaker never actually went to Pixley at all BRain in California in winter is impossible CA week-long window with no amount is easy to meet DThe promise was made to a rival San Francisco newspaper

4. Question 4 of 20 · Multiple Choice

   Macfarlane writes that at San Antonio, "After ten minutes the balloon was exploded, and the rain almost immediately diminished so as to be scarcely perceptible" (Source 8, paragraph 5). How does this observation bear on the concussion claim?

   AIt shows the explosion made the rain heavier BIt runs against the claim that jarring brings rain CIt proves that no rain at all fell anywhere that night DIt shows the General had left the hotel then

5. Question 5 of 20 · Multiple Choice

   Sanford notes that the storm's center sat "near Keeler, about ninety miles east of Pixley" for thirty-six hours (Source 2, paragraph 4). What does this detail add to his argument?

   AA large storm close by can explain the rain BKeeler was the place where Baker worked CThe storm missed Pixley completely that week DNinety miles is too far for any rain to travel

6. Question 6 of 20 · Multiple Choice

   Sanford adds that "During Monday and Tuesday light rains were reported over nearly all parts of the State" (Source 2, paragraph 4). Which claim in the certificate does this most directly challenge?

   AThat it rained at Pixley on two days late in January BThat six named men signed the certificate CThat the rain was local and covered a small area DThat the rain fell in the month of January

7. Question 7 of 20 · Multiple Choice

   Sanford writes, "At the present time, however, there is no evidence to show that even the smallest local shower has been produced artificially" (Source 3). What does "At the present time" do to his claim?

   AIt limits the claim to the evidence so far BIt shows he thinks rain-making will work soon CIt admits he has read no rain-making reports DIt turns the claim into a personal attack

8. Question 8 of 20 · Multiple Choice

   Sanford says that being "able to submit testimony as to the efficacy of their system is equally true of every patent-medicine fraud" (Source 3). What point is he making about evidence?

   ATestimony is the strongest kind of evidence BTestimony alone cannot show that a method works CPatent medicines really did cure the people who bought them DRain-makers never collected any testimony

9. Question 9 of 20 · Multiple Choice

   Sanford reports that at San Antonio, after the firing, "No rain appeared" (Source 4, paragraph 3). How does Source 8 complicate this summary?

   AMacfarlane says the tests were never held BMacfarlane says the rain fell before 4 p. m. CMacfarlane says Sanford ran the San Antonio test DMacfarlane heard rain fall at 1.30 that night

10. Question 10 of 20 · Multiple Choice

    Sanford says the first $2,000 paid for a "preliminary test" by Department of Agriculture scientists before Dyrenforth "came forward" (Source 4, paragraph 1). Harrington says the appropriation went "first of $2,000, then of $7,000" to experiments run by Dyrenforth (Source 5, paragraph 1). What is the most careful conclusion?

    ASanford's version must be right because he is a physicist BThe sources disagree, and these two cannot settle it CHarrington's version must be wrong because it is later DBoth say Dyrenforth received all $9,000 himself

11. Question 11 of 20 · Multiple Choice

    Source 7A says, "Every business downtown benefited." Which source most directly challenges this claim?

    ASource 7B, the four shops' sales BSource 7C, the sales-tax receipts CSource 7D, the bakery owner DSource 7E, the weather note

12. Question 12 of 20 · Multiple Choice

    What is the main weakness of the evidence in Source 7B?

    AIt gives the sales in dollars and not in numbers of items BIt covers more months than the claim does CIt comes from the city finance office DThe organizers picked four market sellers

13. Question 13 of 20 · Multiple Choice

    Source 7B compares May with June. What does Source 7E suggest about that comparison?

    ABetter weather in June may explain some growth BRain in May proves the market caused the growth CJune had more rainy days than May did DThe weather note makes the 25% figure exact

14. Question 14 of 20 · Multiple Choice

    Which use of evidence best tests the claim that the market "boosted downtown sales"?

    AComparing four chosen shops from May to June BQuoting the bakery owner's complaint at length CCounting the rainy days in May and in June DComparing all downtown in June with last June

15. Question 15 of 20 · Short Answer

    Audit Dyrenforth's first conclusion (Source 5, paragraph 3): "the jarring of the cloud by concussions will cause the particles of moisture in suspension to agglomerate and fall". Critique the claim, then critique the evidence that Sanford gives against it in Source 4, paragraph 3.

    Show model answer

16. Question 16 of 20 · Short Answer

    Macfarlane writes that "no care was taken to observe whether rain did fall" under the 10.15 balloon (Source 8, paragraph 3), and later reports the General saying, "There is a beautiful rain to the north of us and to the west of us" (paragraph 6). Critique how the experimenters used evidence that night.

    Show model answer

17. Question 17 of 20 · Short Answer

    Critique Macfarlane as a witness (Source 8). Name two strengths and one limitation of his evidence.

    Show model answer

18. Question 18 of 20 · Short Answer

    Answer the compelling question in one paragraph: "How credible were the claims of the 1890s rain-makers, and of their critics?" Audit at least one claim and one use of evidence from each side.

    Show model answer

19. Question 19 of 20 · Short Answer

    Rewrite the claim in Source 7A so that it is credible, using only Sources 7B-7E. Include the change in downtown sales-tax receipts from Source 7C as a percentage.

    Show model answer

20. Question 20 of 20 · Short Answer

    Before voting to pay for the market again, what evidence should the council ask for? Name two kinds of evidence and explain which weakness in Sources 7A-7E each would fix.

    Show model answer

These standards connect to D4.4.9-12: prerequisites to review first, parallel standards at the same level, and next steps that build on it.

Standard text: National Council for the Social Studies (NCSS), The College, Career, and Civic Life (C3) Framework for Social Studies State Standards: Guidance for Enhancing the Rigor of K-12 Civics, Economics, Geography, and History (Silver Spring, MD: NCSS, 2013). NCSS was not involved in the production of this lesson and does not endorse it.