02: Content Structuring

Example

The following example demonstrates how to correctly structure source content.

Input

The Animal kingdom: Animals are typically classified into two groups: vertebrates and invertebrates. Vertebrates are animals with backbones. These can be classified into mammals, birds, reptiles, amphibians, and fish. Invertebrates are animals without backbones. These include molluscs, arthropods, worms, echinoderms, and coelenterates.

Mammals: Mammals are warm-blooded vertebrate animals that have hair or fur. They have four limbs and many have tails. There is a very wide range of types in this group, from the 30-millimeter bumblebee bat to the 33-meter blue whale. Mammals breathe air, and they live on land or in the sea. Almost all mammals give birth to live young ones. They retain the young in their bodies until they are ready to be born. When the young ones are born, they are fed by the mother on milk. Marsupials are a subset of mammals, which lay eggs but give milk to their young ones. Unlike plants, mammals need to eat other living things to live. So, they could be herbivorous (i.e., eating plants) or carnivorous (i.e., eating other animals) or both. Examples of mammals include human beings, dogs, cats, lions, bears, elephants, rabbits, cows, and horses.

Birds: Birds are warm-blooded vertebrate animals whose bodies are covered with feathers. They have two legs and two wings. They range in size from the five-centimeter bee hummingbird to the three-meter ostrich. Most birds are carnivorous. All birds breathe air, and live on land. They have a lightweight but strong skeleton to enable flight. Many birds migrate long distances during winter. Most birds are carnivorous. They have a hard beak instead of a mouth for eating. Female birds lay hard-shelled eggs and the young ones hatch from these. The young ones are cared for by the adult birds until they are old enough to fend for themselves. Fossil records indicate that birds emerged from dinosaurs around 160 million years ago. Bats are not birds but mammals. Examples of birds include chickens, crows, parrots, pigeons, eagles, and vultures. Ostriches, emus, kiwis, and penguins are examples of birds that cannot fly.

Reptiles: Reptiles are cold-blooded vertebrate animals. This means they cannot maintain a body temperature much different than their environment. The bodies of reptiles are covered with scales. They have four limbs and a tail. Reptiles are found on land and in water. They breathe air and are carnivorous. Reptiles range in sizes from the tiny gecko, which can grow up to 17 millimeters to the saltwater crocodile, which may reach six meters. Most reptiles lay eggs with hard shells. From these eggs hatch fully formed young ones that are capable of fending for themselves. Reptiles usually lay their eggs in sand. Some snakes and lizards retain their eggs in their body and give birth to live young ones. Reptiles have been on earth for over 300 million years. Examples of reptiles include lizards, snakes, turtles, tortoises, and crocodiles. Some reptiles, like lizards, have the ability to grow their tail back if it is cut off.

Amphibians: Amphibians are also cold-blooded vertebrate animals. They have four limbs. They are characterized by their ability to live both on land and in fresh water. Adult amphibians have lungs to breathe air, but have gills to breathe in water when they are young. They generally spend their larval or tadpole stage in fresh water and move on to land when they mature. They then return to the water to breed. Amphibians lay soft-shelled eggs. The tadpoles are vegetarian but the adults are carnivorous. The skin of amphibians is porous and poisonous. Amphibians are delicate creatures, but can survive long periods of hibernation by slowing down their metabolism. Amphibians were the first pre-historic animals to venture on to land. They emerged from the oceans over 300 million years ago. Frogs, toads, salamanders, and newts are amphibians.

Fish: Fish are cold-blooded vertebrate animals that live in water and use gills to obtain oxygen. Fish live in both fresh and salt water and can be found all over the world, except in some very hot springs and the Dead Sea because it is too salty. The bodies of most fish are covered with scales and do not have limbs. Instead, fish have fins and tail to swim around in water. They are mostly carnivorous. Fish range in size from the tiny eight-millimeter stout infantfish to the huge 16-metre whale shark. Fish lay eggs in large numbers and mostly do not care for their young ones. Fish are abundant in most bodies of water. They can be found in nearly all aquatic environments, from high mountain streams to the abyssal depths of the deepest oceans. At 32,000 species, fish exhibit greater species diversity than any other group of vertebrates. Examples of fish include goldfish, tunas, piranhas, sea horses, eels, rays, and sharks. Whales, dolphins, and seals are not fish but mammals.

Molluscs: Molluscs are soft-bodied invertebrate animals. They live on land, in freshwater, and in the sea. Molluscs have such a varied range of body structures. A typical mollusc body has a mantle with a significant cavity used for breathing and excretion, and a nervous system. The mantle is a hard shell covering the upper body and the underside is a single muscular foot. Most molluscs have eyes, and all have sensors that detect chemicals, vibrations, and touch. All molluscs produce eggs, from which may emerge larvae or miniature adults. A striking feature of molluscs is the use of the same organ for multiple functions. For example, the heart and kidneys are important parts of the reproductive system as well as the circulatory and excretory systems; the gills both breathe and produce a water current in the mantle cavity, which is important for excretion and reproduction. Examples of molluscs include snails, slugs, oysters, clams, cuttle-fish, squids, and octopus.

Arthropods: Arthropods are invertebrate animals having an external skeleton, a segmented body, and jointed appendages. They include insects, spiders, and shell-fish. Their skeleton inhibits growth, so arthropods regularly shed their skin. Their bodies are built of repeating segments, both externally and internally. Owing to this simple yet very successful body design, arthropods are the largest group of animals on earth, accounting for over 80% of all animal species. They live on land, in water (including marine), and many can fly. Their sizes vary widely from the microscopic plankton to the four-meter-long Japanese spider crab. Almost all arthropods lay eggs, but scorpions give birth to live young after the eggs have hatched inside the mother. Arthropod hatchlings vary from miniature adults to grubs and caterpillars that lack jointed limbs and eventually undergo a total metamorphosis to produce the adult form. The level of maternal care for hatchlings varies from nonexistent to the prolonged care provided by scorpions.

Worms: Worms are elongated, soft-bodied invertebrate animals. Their bodies are divided into a number of similar rings. The head tapers to a point and the tail is broad and flat. They do not have limbs. The pores on the skin cover its body with slime. This slime keeps the worm clean, makes it slippery, and kills germs. The pointed nose drills into the soil and the flat tail presses it tight. The slime is then used to cement the burrows. Worms vary in size from microscopic to over one meter in length for marine bristle worms, 6.7 meters for the African giant earthworm, and 55 meters for the marine bootlace worms. They may live on land, in water, and even inside the bodies of other animals. Examples of worms include tapeworm, earthworm, and silkworm. Ringworm is not a worm at all, but a skin fungus.

Echinoderms: Echinoderm is a common name for about 6,000 living species that live on the sea floor at all depths in all of the oceans of the world. Starfish and sea-urchins are the most common of echinoderms. Starfish have a mouth surrounded by five arms. At the ends of the arms are fleshy tube-feet, which the starfish uses to cling to things and to crawl about. Sea-urchins have spines that are very well developed. Echinoderms have simple nervous and circulatory systems. They are remarkable for their tissue regenerative abilities. A starfish arm cut off will regenerate. A section as small as a single arm, with some central disk and neural tissue, can regenerate the whole organism. Examples of echinoderms include starfish, brittle-stars, sea-urchins, sea-cucumbers, sea-lilies, and feather-stars.

Coelenterates: Coelenterate is the common name for 9,000 species of invertebrate animals found in all oceans of the world. Their bodies are symmetrical, soft, and hollow with two layers of tissue. They are slow-moving marine creatures. Coelenterates include coral, hydras, jellyfish and sea-anemone. Some are cylindrical with a mouth and tentacles at one end. Jellyfish look like an open umbrella with hanging tentacles. Coelenterates have toxins to defend against predators. All coelenterates capture their prey in the tentacles and then kill them with poison from a stinging organ. Coelenterates are simple organisms. They do not have a brain, but a simple nervous system called a nerve net for basic smell and taste. Both their digestive and circulatory are meshed up. They breathe through their body surface.

Output

Module 1: Animal Kingdom

          Lesson 1: Vertebrates

                   Topic 1: Mammals

                   Topic 2: Birds

                   Topic 3: Reptiles

                   Topic 4: Amphibians

                   Topic 5: Fish

          Lesson 2: Invertebrates

                   Topic 6: Arthropods

                   Topic 7: Worms

                   Topic 8: Molluscs

                   Topic 9: Echinoderms

                   Topic 10: Coelenterates

In this example, as per the chunked concepts, the chunks are classified into module-lesson-topic, from the known to the unknown.

Non-Example

The following non-example demonstrates how not to structure source content.

Input

The Animal kingdom: Animals are typically classified into two groups: vertebrates and invertebrates. Vertebrates are animals with backbones. These can be classified into mammals, birds, reptiles, amphibians, and fish. Invertebrates are animals without backbones. These include molluscs, arthropods, worms, echinoderms, and coelenterates.

Mammals: Mammals are warm-blooded vertebrate animals that have hair or fur. They have four limbs and many have tails. There is a very wide range of types in this group, from the 30-millimeter bumblebee bat to the 33-meter blue whale. Mammals breathe air, and they live on land or in the sea. Almost all mammals give birth to live young ones. They retain the young in their bodies until they are ready to be born. When the young ones are born, they are fed by the mother on milk. Marsupials are a subset of mammals, which lay eggs but give milk to their young ones. Unlike plants, mammals need to eat other living things to live. So, they could be herbivorous (i.e., eating plants) or carnivorous (i.e., eating other animals) or both. Examples of mammals include human beings, dogs, cats, lions, bears, elephants, rabbits, cows, and horses.

Birds: Birds are warm-blooded vertebrate animals whose bodies are covered with feathers. They have two legs and two wings. They range in size from the five-centimeter bee hummingbird to the three-meter ostrich. Most birds are carnivorous. All birds breathe air, and live on land. They have a lightweight but strong skeleton to enable flight. Many birds migrate long distances during winter. Most birds are carnivorous. They have a hard beak instead of a mouth for eating. Female birds lay hard-shelled eggs and the young ones hatch from these. The young ones are cared for by the adult birds until they are old enough to fend for themselves. Fossil records indicate that birds emerged from dinosaurs around 160 million years ago. Bats are not birds but mammals. Examples of birds include chickens, crows, parrots, pigeons, eagles, and vultures. Ostriches, emus, kiwis, and penguins are examples of birds that cannot fly.

Reptiles: Reptiles are cold-blooded vertebrate animals. This means they cannot maintain a body temperature much different than their environment. The bodies of reptiles are covered with scales. They have four limbs and a tail. Reptiles are found on land and in water. They breathe air and are carnivorous. Reptiles range in sizes from the tiny gecko, which can grow up to 17 millimeters to the saltwater crocodile, which may reach six meters. Most reptiles lay eggs with hard shells. From these eggs hatch fully formed young ones that are capable of fending for themselves. Reptiles usually lay their eggs in sand. Some snakes and lizards retain their eggs in their body and give birth to live young ones. Reptiles have been on earth for over 300 million years. Examples of reptiles include lizards, snakes, turtles, tortoises, and crocodiles. Some reptiles, like lizards, have the ability to grow their tail back if it is cut off.

Amphibians: Amphibians are also cold-blooded vertebrate animals. They have four limbs. They are characterized by their ability to live both on land and in fresh water. Adult amphibians have lungs to breathe air, but have gills to breathe in water when they are young. They generally spend their larval or tadpole stage in fresh water and move on to land when they mature. They then return to the water to breed. Amphibians lay soft-shelled eggs. The tadpoles are vegetarian but the adults are carnivorous. The skin of amphibians is porous and poisonous. Amphibians are delicate creatures, but can survive long periods of hibernation by slowing down their metabolism. Amphibians were the first pre-historic animals to venture on to land. They emerged from the oceans over 300 million years ago. Frogs, toads, salamanders, and newts are amphibians.

Fish: Fish are cold-blooded vertebrate animals that live in water and use gills to obtain oxygen. Fish live in both fresh and salt water and can be found all over the world, except in some very hot springs and the Dead Sea because it is too salty. The bodies of most fish are covered with scales and do not have limbs. Instead, fish have fins and tail to swim around in water. They are mostly carnivorous. Fish range in size from the tiny eight-millimeter stout infantfish to the huge 16-metre whale shark. Fish lay eggs in large numbers and mostly do not care for their young ones. Fish are abundant in most bodies of water. They can be found in nearly all aquatic environments, from high mountain streams to the abyssal depths of the deepest oceans. At 32,000 species, fish exhibit greater species diversity than any other group of vertebrates. Examples of fish include goldfish, tunas, piranhas, sea horses, eels, rays, and sharks. Whales, dolphins, and seals are not fish but mammals.

Molluscs: Molluscs are soft-bodied invertebrate animals. They live on land, in freshwater, and in the sea. Molluscs have such a varied range of body structures. A typical mollusc body has a mantle with a significant cavity used for breathing and excretion, and a nervous system. The mantle is a hard shell covering the upper body and the underside is a single muscular foot. Most molluscs have eyes, and all have sensors that detect chemicals, vibrations, and touch. All molluscs produce eggs, from which may emerge larvae or miniature adults. A striking feature of molluscs is the use of the same organ for multiple functions. For example, the heart and kidneys are important parts of the reproductive system as well as the circulatory and excretory systems; the gills both breathe and produce a water current in the mantle cavity, which is important for excretion and reproduction. Examples of molluscs include snails, slugs, oysters, clams, cuttle-fish, squids, and octopus.

Arthropods: Arthropods are invertebrate animals having an external skeleton, a segmented body, and jointed appendages. They include insects, spiders, and shell-fish. Their skeleton inhibits growth, so arthropods regularly shed their skin. Their bodies are built of repeating segments, both externally and internally. Owing to this simple yet very successful body design, arthropods are the largest group of animals on earth, accounting for over 80% of all animal species. They live on land, in water (including marine), and many can fly. Their sizes vary widely from the microscopic plankton to the four-meter-long Japanese spider crab. Almost all arthropods lay eggs, but scorpions give birth to live young after the eggs have hatched inside the mother. Arthropod hatchlings vary from miniature adults to grubs and caterpillars that lack jointed limbs and eventually undergo a total metamorphosis to produce the adult form. The level of maternal care for hatchlings varies from nonexistent to the prolonged care provided by scorpions.

Worms: Worms are elongated, soft-bodied invertebrate animals. Their bodies are divided into a number of similar rings. The head tapers to a point and the tail is broad and flat. They do not have limbs. The pores on the skin cover its body with slime. This slime keeps the worm clean, makes it slippery, and kills germs. The pointed nose drills into the soil and the flat tail presses it tight. The slime is then used to cement the burrows. Worms vary in size from microscopic to over one meter in length for marine bristle worms, 6.7 meters for the African giant earthworm, and 55 meters for the marine bootlace worms. They may live on land, in water, and even inside the bodies of other animals. Examples of worms include tapeworm, earthworm, and silkworm. Ringworm is not a worm at all, but a skin fungus.

Echinoderms: Echinoderm is a common name for about 6,000 living species that live on the sea floor at all depths in all of the oceans of the world. Starfish and sea-urchins are the most common of echinoderms. Starfish have a mouth surrounded by five arms. At the ends of the arms are fleshy tube-feet, which the starfish uses to cling to things and to crawl about. Sea-urchins have spines that are very well developed. Echinoderms have simple nervous and circulatory systems. They are remarkable for their tissue regenerative abilities. A starfish arm cut off will regenerate. A section as small as a single arm, with some central disk and neural tissue, can regenerate the whole organism. Examples of echinoderms include starfish, brittle-stars, sea-urchins, sea-cucumbers, sea-lilies, and feather-stars.

Coelenterates: Coelenterate is the common name for 9,000 species of invertebrate animals found in all oceans of the world. Their bodies are symmetrical, soft, and hollow with two layers of tissue. They are slow-moving marine creatures. Coelenterates include coral, hydras, jellyfish and sea-anemone. Some are cylindrical with a mouth and tentacles at one end. Jellyfish look like an open umbrella with hanging tentacles. Coelenterates have toxins to defend against predators. All coelenterates capture their prey in the tentacles and then kill them with poison from a stinging organ. Coelenterates are simple organisms. They do not have a brain, but a simple nervous system called a nerve net for basic smell and taste. Both their digestive and circulatory are meshed up. They breathe through their body surface.

Output

Module 1: Animal Kingdom

          Topic 1: Mammals

          Topic 2: Birds

          Topic 3: Reptiles

          Topic 4: Amphibians

          Topic 5: Fish

          Topic 6: Molluscs

          Topic 7: Arthropods

          Topic 8: Worms

          Topic 9: Echinoderms

          Topic 10: Coelenterates

In this non-example, the chunked concepts are classified into module and topics. The lesson chunk is missing. This causes a disturbance in the module-lesson-topic structure of content delivery.