Group Leader Training Materials 1.3 2008/03/25 14:05:14 GMT-5 2008/07/19 00:15:43.304 GMT-5 Cain Project cainproject@mailman.rice.edu Cain Project cainproject@mailman.rice.edu Communication Discussion Writing This document contains materials to be used by an instructor or teaching assistant in the training of Discussion Group Leaders. The goal of the training with these materials is to teach Group Leaders how to grade discussion write-ups. For more information on discussion groups and Group Leaders, see the Group Leader Handbook.

Overview When large lecture classes incorporate small group discussions, the discussion sessions are typically overseen by Group Leaders—undergraduate or graduate students who organize the group’s meetings, assign roles to group members, and answer questions that group members are unable to answer. After each discussion session, one member (the assigned “writer” for a topic) writes a short summary (often called the “write-up”) of the material discussed by the group. This write-up is then graded by the Group Leader. This document prepares Group Leaders for the responsibility of grading these write-ups. The materials here are designed to be used by the course instructor, teaching assistant, or other individual who will act as a “trainer.” The training typically requires about two hours. Ideally, all Group Leaders must be present at the same training session—this is important to ensure as much standardization of grading as possible. The meeting should be held in a conference room containing a whiteboard. At the beginning of the meeting, the trainer passes out Sample discussion question and answer in this document and acquaints the Group Leaders with the sample discussion question and answer. He/she then passes out three copies of the annotated assessment sheet and discusses the grading criteria and the examples in the annotations. After the Group Leaders have become familiar with the discussion question and the “correct and complete” answer to that question, the trainer distributes the first unannotated sample paper (example 1) and allows the Group Leaders to work independently to grade it. An annotated version of the paper (example 4) is provided in this document to familiarize the trainer with the types of comments that might be made. After everyone has finished grading the paper, the trainer then leads a discussion. The following questions may lead the discussion: Did anyone find any inaccuracies in this sample? If so, what are they? How many points were given for “accuracy” by each of you? Why? What problems with clarity or audience-appropriateness were found? How many points did each of you give for that category? Why? Did this summary completely cover the answer to the question? Were the discussion and description covered in sufficient depth? How many points did you each award for “depth/completeness”? Were there any problems with style or organization? What were they? How many points did this paper earn for that criterion? Why? The trainer may use the white board to make notes for the group and keep track of individuals’ point allocations. Group Leaders and the trainer discuss the “standards” for awarding points until a group consensus is reached. At this point, the trainer distributes papers #2 and #3 for grading. Versions of these papers with limited annotation are provided for the trainer’s use. After the Group Leaders have finished grading the papers, the trainer leads a discussion similar to that described above. The goal of the process is to reach a common understanding of how to use the assessment sheet so that the grading will be as standardized as possible.

Sample discussion question and answer

Sample discussion question/topic used in today’s training: The digestive system is designed to break down food that is similar in composition to the animal that is digesting it. What are the mechanisms used to break down food into compounds to be absorbed and how does the digestive system protect itself from these mechanisms? To apply grading criteria in the assessment sheet on the following page, you must know the “answers” to the questions above. This table summarizes all of the organs involved in digestion, the processes that occur in each, and the methods of digestive system protection. As you read each sample student write-up, look for the concepts and keywords in this table. If a student fails to describe any of these processes completely and accurately, you must note it in the “Accuracy” and/or “Depth/completeness” parts of the assessment sheet. Be aware that the information provided here is for training purposes. Group Leaders may or may not be provided with “answers” by actual course instructors. Group Leaders are expected to prepare for actual discussion sessions by reviewing each discussion topic in depth beforehand.

Assessment sheet with annotated examples from sample question This assessment sheet contains examples of errors (not errors in the samples used in training today). As you grade today’s sample papers, try to rate each paper on each criterion, using the example errors to guide your ratings. Half-points may be awarded in each 3 point-scale.

Samples Sample write-up No.1 for practice grading by Group Leaders The digestive system is designed to break down food that is similar in composition to the animal that is digesting it. What are the mechanisms used to break down food into compounds to be absorbed and how does the digestive system protect itself from these mechanisms? The digestion of food occurs mainly in the mouth, stomach, and small intestine. In the mouth, food is both mechanically and chemically broken down. Mastication (chewing) mechanically breaks down (reduces the size of) food, while oral amylase (an enzyme secreted by the salivary glands) breaks down carbohydrates and oral lipase (an enzyme secreted by the tongue) breaks down triglycerides into fatty acids and monoglycerides. The inside of the mouth is protected from these digestive mechanisms by a thick layer of epithelial cells and a slimy substance called mucus. After swallowing, food moves through the esophagus to the stomach. No real digestion occurs in the esophagus. Once in the stomach, the digestion of food continues. The lining of the stomach is made up of chief, parietal and goblet cells. Chief cells synthesize and store Pepsinogen, a precursor to the enzyme Pepsin. Pepsin digests proteins in the stomach. In order for the Pepsin to not “digest” the cells it is synthesized within, it is synthesized in its inactive form, Pepsinogen. However, once the enzyme is secreted, the acidic nature of the stomach turns it into its active form, Pepsin. Parietal cells secrete hydrochloric acid (HCl), which helps break down the food. At the height of digestion the pH of the stomach can reach 1.5, which is dangerously acidic to unprotected tissue. The stomach is able to protect itself from the acid it secretes with a layer of mucus produced by the goblet cells. Sometimes this layer fails to protect, and the acid can eat away at the lining of the stomach, causing an ulcer. In most cases this occurs when bacteria that is normally present in the stomach is affected by changes in the body (stress, obesity, etc.). This bacteria causes the mucus lining to thin, which in turn allows the acid to reach the cells in the lining of the stomach. From the stomach the food moves into the small intestine. This is where absorption of most of the nutrients from food occurs. In order to derive useful nutrients from the slush (chyme) from the stomach, the small intestine utilizes a series of enzymes (mostly secreted by the pancreas in inactive form). The main enzyme secreted by the pancreas that aids in digestion is Trypsinogen. Once in the small intestine, another enzyme known as Enterokinase activates Trypsinogen by cleaving it. The active enzyme formed by this reaction is known as Trypsin. Trypsin then activates other inactive forms of digestive enzymes (chymotrypsin, elastase, and carboxypeptidase) in the small intestine. This chain of events leads to the further digestion and preparation for absorption of food. The pancreas is protected from the digestive enzymes it secretes because they are not activated until they are in the small intestine. The pancreas also releases into the small intestine the enzyme pancreatic amylase, which continues digestion of carbohydrates. Nucleases are released to break down food DNA and RNA into nucleotides. Sample write-up No.2 for practice grading by Group Leaders The digestive system is designed to break down food that is similar in composition to the animal that is digesting it. What are the mechanisms used to break down food into compounds to be absorbed and how does the digestive system protect itself from these mechanisms? The Digestive tract starts of in the mouth were the teeth and saliva break down food into smaller pieces. Enzymes in the saliva such as amylase and lipase break down carbohydrates and lipids. Mucus, which is produced when water combines with mucins, water and glycoproteins secreted by the salivary gland in the mouth, aid in food transportation down the Esophagus. The Esophagus transports food to the stomach by way of circular and longitudinal muscle contractions. The stomach is a highly acidic muscular organ that’s main role is to break down materials such as proteins with enzymes, pepsin. Chief cells contain the inactive precursor compound to pepsin pepsinogen that is later activated when in the acidic environment of the stomach. The acidic environment of the stomach begins in the parietal cells of the stomach lining. The parietal cells contain a high concentration of an enzyme called carbonic anhydrase which catalyze the formation of H2CO3, that in solution splits to a H+ and HCO3. When the HCO3 is transported out of epithelial cells and into the blood stream Cl- comes into the epithelial cells. Chlorine exits through the epithelial cells and into the lumen though a Cl- channel and the proton will enter through a proton pump. The HCl in the stomach break down food into chyme, then the chyme is transported to the small intestine. The small intestine continues to process materials (carbohydrates, lipids, and proteins) with enzymes from the pancreas and liver. Enterokinase activates pancreatic typsinogen by phosphorylating it which results in trypsin and triggering other protein digesting enzymes that break down polypeptides into amino acid monomers. Cholecystokinin stimulate secretion of molecules from liver and pancreas involved in digesting lipids. Bile salts synthesized in the liver, enter the small intestine raise the pH and emulsify fats. The Pancreas releases nucleases that digest RNA and DNA in food along with pancreatic amylase that continues to denature carbs. The epithelial cells absorb materials from the lumen of small intestine through the microville on the apical side. A NA+/K+-ATPase pump creates an electrochemical gradient favoring NA+ transport through the Basolateral side and into the blood stream followed by glucose, through a GLUT-2, and water via osmosis. By the time the digested material has reached the large intestine all nutrients and 75 liters of water have been absorbed. The large intestine compacts waste and absorbs any additional water in order to compact feces for excretion. The Esophagus is protected from tears when food is transported down the cells by the mucus secreted in the mouth. Mucus, found in gastric juice, is secreted by goblet cells in the epithelial membrane to protect the stomach lining from damage, ulcers. Acidic materials entering the small intestine trigger secretin to activate and bring HCO3 from the pancreas to neutralize acid. HCO3is a by-product from the break down of H2CO3 in the parietal cells. The gall bladder stores bile salts till triggered for release into the stomach. Sample write-up No.3 for practice grading by Group Leaders The digestive system is designed to break down food that is similar in composition to the animal that is digesting it. What are the mechanisms used to break down food into compounds to be absorbed and how does the digestive system protect itself from these mechanisms? Humans ingest three types of macromolecules: carbohydrates, lipids, and proteins. These types of food are broken down and absorbed by the digestive system. Digestion begins in the mouth where carbohydrates are broken down into glucose by the enzyme amylase located in the saliva. Cells in the tongue secrete the enzyme lipase that begins the digestion of lipids by turning them into fatty acids and monoglycerides. Salivary glands release water and glycoproteins called mucins that come in contact with water to form mucus. The substance mucus allows food to be soft and slippery so that it can be swallowed. From the mouth, food enters the esophagus, here very little digestion occurs, and is used as a pathway to the stomach. Waves of muscle contractions, peristalsis, move food particles down the esophagus into the stomach. The environment in the stomach is very acidic, sometimes with 1.5 pH. To keep the acid contained within the stomach there are sphincters closing the stomach off from the esophagus and small intestine. The lining of the stomach is protected by mucus secreted from goblet cells located within the lining; if the lining is damaged ulcers can form. Proteins are broken down by the enzyme pepsin, which is stored in chief cells as the inactive pesinogen. Perinogen becomes pepsin once it comes in contact with the acid of the stomach. In the small intestine the DNA and RNA of carbohydrates are digested by nucleases, and pancreatic amylase continues the digestion that began in the mouth. The sugars released are absorbed by villi on the epithelial tissue. Lipids are broken down by the enzyme lipase, after the fat is broken down, emulsified, by bile entering the small intestine and raising the pH. The enzyme enterokinase(from small intestine) phosphorilates the enzyme trypsinogen (from pancreas) to form tyrpsin. This enzyme then activates chymotrypsin, elastase, and carboxypeptidase, all of which are protein-digesting enzymes from the pancreas. During the discussion we talked about the different types of diabetes. In type I the pancreas produces no insulin, the hormone involved with lowering blood-glucose levels when they are high. Type II individuals produce insulin, but there is a problem with the receptor. We concluded that heartburn is a result of the stomach’s acid entering the esophagus; however we could not explain what causes stomach aches. We were also wondering how they treat stomach ulcers, none of us could find out an explanation. At the end of the discussion we were informed that a Nobel Prize was given this year to scientists who discovered that ulcers were caused by infection not stress. In order to treat an ulcer, a patient must be given a round of antibiotics. Sample write-up No.1 with annotations, for trainer use The digestive system is designed to break down food that is similar in composition to the animal that is digesting it. What are the mechanisms used to break down food into compounds to be absorbed and how does the digestive system protect itself from these mechanisms? The digestion of food occurs mainly in the mouth, stomach, and small intestine. In the mouth, food is both mechanically and chemically broken down. Mastication [Comment1] (chewing) mechanically breaks down (reduces the size of) food, while oral amylase (an enzyme secreted by the salivary glands) breaks [Comment2] down carbohydrates and oral lipase (an enzyme secreted by the tongue) breaks down triglycerides into fatty acids and monoglycerides. The [Comment3] inside of the mouth is protected from these digestive mechanisms by a thick layer of epithelial cells and a slimy substance called mucus[Comment4]. After [Comment5] swallowing, food moves through the esophagus to the stomach. No real digestion occurs in the esophagus. Once in the stomach, the digestion of food continues. The lining of the stomach is made up of chief, parietal and goblet cells. Chief cells synthesize and store Pepsinogen, a precursor to the enzyme Pepsin. Pepsin digests proteins in the stomach. In order for the Pepsin to not “digest” the cells it is synthesized within, it is synthesized in its inactive form, Pepsinogen. However, once the enzyme is secreted, the acidic nature of the stomach turns it into its active form, Pepsin. Parietal cells secrete hydrochloric acid (HCl), which helps break down the food. At the height of digestion the pH of the stomach can reach 1.5, which is dangerously acidic to unprotected tissue. The stomach is able to protect itself from the acid it secretes with a layer of mucus produced by the goblet cells. Sometimes this layer fails to protect, and the acid can eat away at the lining of the stomach, causing an ulcer. In most cases this occurs when bacteria that is [Comment6] normally present in the stomach is affected by changes in the body (stress, obesity, etc.). This bacteria [Comment7]causes the mucus lining to thin, which in turn allows the acid to reach the cells in the lining of the stomach [Comment8]. From [Comment9] the stomach the food moves into the small intestine. This is where absorption of most of the nutrients from food occurs. In order to derive useful nutrients from the slush (chyme) from the stomach, the small intestine utilizes a series of enzymes (mostly secreted by the pancreas in inactive form). The main enzyme secreted by the pancreas that aids in digestion is Trypsinogen. Once in the small intestine, another enzyme known as Enterokinase activates Trypsinogen by cleaving it. The active enzyme formed by this reaction is known as Trypsin. Trypsin then activates other inactive forms of digestive enzymes (chymotrypsin, elastase, and carboxypeptidase) in the small intestine. This chain of events leads to the further digestion and preparation for absorption of food. The pancreas is protected from the digestive enzymes it secretes because they are not activated until they are in the small intestine. The pancreas also releases into the small intestine the enzyme pancreatic amylase, which continues digestion of carbohydrates. Nucleases are released to break down food DNA and RNA into nucleotides [Comment10, 11]. Sample write-up No.2 with limited annotations, for trainer use The digestive system is designed to break down food that is similar in composition to the animal that is digesting it. What are the mechanisms used to break down food into compounds to be absorbed and how does the digestive system protect itself from these mechanisms? The [Comment12] Digestive tract starts of in the mouth were the teeth and saliva break down food into smaller pieces. Enzymes in the saliva such as amylase and lipase break down carbohydrates and lipids. Mucus, which is produced when water combines with mucins, water and glycoproteins secreted by the salivary gland in the mouth, aid in food transportation down the Esophagus. The Esophagus transports food to the stomach by way of circular and longitudinal muscle contractions. The stomach is a highly acidic muscular organ that’s main role is to break down materials such as proteins with enzymes, pepsin. Chief cells contain the inactive precursor compound to pepsin pepsinogen that is later activated when in the acidic environment of the stomach. The acidic environment of the stomach begins in the parietal cells of the stomach lining. The parietal cells contain a high concentration of an enzyme called carbonic anhydrase which catalyze the formation of H2CO3, that in solution splits to a H+ and HCO3. When the HCO3 is transported out of epithelial cells and into the blood stream Cl- comes into the epithelial cells. Chlorine exits through the epithelial cells and into the lumen though a Cl- channel and the proton will enter through a proton pump. The HCl in the stomach break down food into chyme, then the chyme is transported to the small intestine. The small intestine continues to process materials (carbohydrates, lipids, and proteins) with enzymes from the pancreas and liver. Enterokinase activates pancreatic typsinogen by phosphorylating it which results in trypsin and triggering other protein digesting enzymes that break down polypeptides into amino acid monomers [Comment13]. Cholecystokinin stimulate secretion of molecules from liver and pancreas involved in digesting lipids. Bile salts synthesized in the liver, enter the small intestine raise the pH and emulsify fats. The Pancreas releases nucleases that digest RNA and DNA in food along with pancreatic amylase that continues to denature carbs. The epithelial cells absorb materials from the lumen of small intestine through the microville on the apical side. A NA+/K+-ATPase pump creates an electrochemical gradient favoring NA+ transport through the Basolateral side and into the blood stream followed by glucose, through a GLUT-2 [Comment14], and water via osmosis. By the time the digested material has reached the large intestine all nutrients and 75 liters of water have been absorbed. The large intestine compacts waste and absorbs any additional water in order to compact feces for excretion. The Esophagus is protected from tears when food is transported down the cells by the mucus secreted in the mouth. Mucus, found in gastric juice, is secreted by goblet cells in the epithelial membrane to protect the stomach lining from damage, ulcers. Acidic materials entering the small intestine trigger secretin to activate and bring HCO3 from the pancreas to neutralize acid. HCO3is a by-product from the break down of H2CO3 in the parietal cells. The gall bladder stores bile salts till triggered for release into the stomach [Comment15,16]. Sample write-up No.3 with limited annotations, for trainer use The digestive system is designed to break down food that is similar in composition to the animal that is digesting it. What are the mechanisms used to break down food into compounds to be absorbed and how does the digestive system protect itself from these mechanisms? Humans ingest three types of macromolecules: carbohydrates, lipids, and proteins. These types of food are broken down and absorbed by the digestive system. Digestion begins in the mouth where carbohydrates are broken down into glucose by the enzyme amylase located in the saliva. Cells [Comment17] in the tongue secrete the enzyme lipase that begins the digestion of lipids by turning them into fatty acids and monoglycerides. Salivary glands release water and glycoproteins called mucins that come in contact with water to form mucus. The substance mucus allows food to be soft and slippery so that it can be swallowed. From the mouth, food enters the esophagus, here very little digestion occurs, and [Comment18] is used as a pathway to the stomach. Waves of muscle contractions, peristalsis, move food particles down the esophagus into the stomach. The environment in the stomach is very acidic, sometimes with 1.5 pH. To keep the acid contained within the stomach there are sphincters closing the stomach off from the esophagus and small intestine. The lining of the stomach is protected by mucus secreted from goblet cells located within the lining; if the lining is damaged ulcers can form. Proteins are broken down by the enzyme pepsin, which is stored in chief cells as the inactive pesinogen. Perinogen becomes pepsin once it comes in contact with the acid of the stomach. In the small intestine the DNA and RNA of carbohydrates are [Comment19] digested by nucleases, and pancreatic amylase continues the digestion that began in the mouth. The sugars released are absorbed by villi on the epithelial tissue. Lipids are broken down by the enzyme lipase, after the fat is broken down, emulsified, by bile entering the small intestine and raising the pH [Comment20]. The enzyme enterokinase(from small intestine) phosphorilates the enzyme trypsinogen (from pancreas) to form tyrpsin. This enzyme then activates chymotrypsin, elastase, and carboxypeptidase, all of which are protein-digesting enzymes from the pancreas. During the discussion we talked about the different types of diabetes. In type I the pancreas produces no insulin, the hormone involved with lowering blood-glucose levels when they are high. Type II individuals produce insulin, but there is a problem with the receptor. We concluded that heartburn is a result of the stomach’s acid entering the esophagus; however we could not explain what causes stomach aches. We were also wondering how they treat stomach ulcers, none of us could find out an explanation. At the end of the discussion we were informed that a Nobel Prize was given this year to scientists who discovered that ulcers were caused by infection not stress. In order to treat an ulcer, a patient must be given a round of antibiotics [Comment21]. Comments: Writer is aware of audience’s need for definitions. Writer overuses parentheses, but this minor style error does not interfere with reader’s understanding of the content. Writing is logical and flows well. Paragraph covers all the required information about digestion in the mouth. Logical place for a paragraph break: from mouth to stomach. The word “bacteria” is plural, so the writer should have used “are,” but this is a minor error, not worthy of point deduction. “Bacteria” is a plural word (see above comment). This paragraph covers all the required information about digestion and protection in the stomach. Another logical paragraph break. Sentences in this sample are a bit choppy, but the writing is still clear and perfectly acceptable. No mention of bile; otherwise, the content is complete and accurate. Because the writer did not discuss bile, its origin, or its function, the omission is worth a full one-point drop in the “depth/completeness” category, but not two points (which might have been the case if several processes in the small intestine had been omitted). Overall score: 11/12. Accuracy 3/3; Clarity/audience 3/3; Depth/completeness 2/3; Style/organization 3/3. One very long paragraph for multiple, discrete ideas (example of organization error) and multiple spelling and grammatical errors, as shown in boldface font in the first five sentences (examples of style errors). Writer does not name trypsin substrates chymotrypsin, elastase, and carboxypeptidases. (Example of completeness error) Inappropriate for audience because the term GLUT-2 is not defined. (Example of audience-appropriateness error) Overall score: 6.5/12. Accuracy 2/3; Clarity/audience 2.5/3; Depth/completeness 1/3; Style/organization 1/3. Bile is released into the intestine, not the stomach. (Example of accuracy error) Writer fails to mention the physical breakdown of food by chewing. (Example of completeness error) The minor style error here is not worth marking down because the reader can still reasonably understand the writer; however, if the writer makes these kinds of errors repeatedly, the style grade can be marked down one point. Carbohydrates do not have DNA or RNA. (Example of accuracy error) This sentence is very awkward. The ideas are not logically organized or grammatically correct. (Example of style/organization error) Overall score: 9/12. Accuracy 2/3; Clarity/audience 3; Depth/completeness 2.5/3; Style/organization 2/3Download version: Group Leader Training Materials.