The same 46! By comparison, each row of the table would include unique values for each of the described columns; our table would contain numerous rows, each one representing a single person. First elaborated by Edgar F. Codd, the Normal Forms provide criteria for designing database tables in such a way that risks of data compromise and inconsistencies are limited. Normalizing tables often also has the corollary effect of rendering data stores more efficient and flexible.
Let's consider briefly the core principles of the first three of several Normal Forms for tables. This is not intended to be a detailed presentation of Normal Forms, nor the controversies that might surround their definitions.
First Normal Form 1NF : Eliminate duplicate columns from the table in other words, eliminate redundancy and Create separate tables for each group of intrinsically related data, and Identify each row with a unique column a key. Second Normal Form 2NF Meet all the requirements of the first normal form, and Remove subsets of data that apply to multiple rows of a table and place them in separate tables, and Create relationships between these new tables and their predecessors through the use of foreign keys.
Third Normal Form 3NF Meet all the requirements of the second normal form, and Remove columns that are not dependent upon the primary key. In 1NF, we gather data into related groups and identify each group table with an identifier or key. The key identifies the row and has no other value to the dataset. In 2NF, we verify that all rows in the table represent the same constructs - a table of people, for example, should not include the name of a commercial enterprise.
Using keys, we create! So, for TablePeople, each row would be identified by a primary key a. A column in the TablePeople for bank accounts would not make sense, according to 3NF, because the TablePeople key defines the person as opposed the banks they use.
Another separate table, TableAccounts, would be better suited to contain this information as 'Bank Account' is a construct completely distinct from 'Person'. Class-based Design The second computing science concept called into play is that of object- oriented design.
Object-oriented programming OOP , first introduced in the s through Simula 67 then formalized and expanded later by IBM as Smalltalk in the early s and others since, allows programmers to model the real world by creating classes of objects, each of which has its own internal workings, and defines its own data and behavior.
Classes are used as a type of flexible template for the creation of course and lesson objects. Given the predictable and well-structured definition of the classes and objects, they may also be recombined as building blocks of new courses and lessons. These classes, and the objects created from them, relate to one another through exposed interfaces and otherwise hide the details of their operations, in other words, they are self-contained. As a metaphor, you might ask a car salesman to accept a certain price on a vehicle and he will give you the answer without divulging the details of how he worked out their response, but he might convey some of the hidden information to a trusted partner, such as the dealership's business manager.
To further the example, the salesman will understand a certain set of data constructs such as English words , but will not know how to manage others such as Finnish. This is to say that classes within an 48! The following are key concepts in OOP as they relate to DE design: Class - A class lists the traits of a thing object , in other words it 'abstracts' the thing - in this case students, instructors, courses and lessons. The class includes the thing's characteristics its attributes, fields or properties and the thing's behaviors the things it can do, or methods.
For example, the class ClassStudent would consist of traits shared by all students, such as firstName, lastName, mailingAddress, emailAddress, and enrollmentStatus characteristics or 'properties' , and the ability to enrollNewClass, dropExistingClass, makePayment, takeTest behaviours or 'methods'. Classes provide modularity and structure in an object-oriented computer program. The inner workings of a class code to a programmer, instructions to an educator should be relatively self-contained, in other words encapsulated.
Collectively, the properties and methods defined by a class are called members. Object - A particular instance of a class. The set of values of the attributes of a particular object is called its state.
The object consists of a particular state and the behaviours defined in the object's class. Method and Properties - As described earlier, methods are an object's abilities, in other words, the things it is allowed to do and designed to accomplish.
Obviously, it makes no sense to design and assign a method ability to a student that the student would or could never use, though students might have methods defined for them that they are conditionally allowed to execute perform.
Properties are simply characteristics, or traits, of the objects. Examples of properties of! Inheritance - 'Subclasses' are more specialized versions of a class, which inherit attributes and behaviors from their parent classes, and can introduce their own.
Clearly, all of these are students, but they have important differences. The subclasses can inherit properties and behaviours but can also add their own tailored members.
ClassMedicalStudent will inherit the basis information required for all students and may add properties and methods to describe medical specialty training and immunization status, but this information would not be required for undergraduates, for example.
Finally, classes may draw traits from not only their parents but also from other classes with which they have permission to communicate. Encapsulation - Encapsulation conceals the functional details of the inner workings of the class from objects that communicate with it. In terms of DE design, encapsulation requires that there be no guessing as to how the lesson be carried out.
The lesson may reference antecedent work inherited through its parent class that is, all students must have some core set of properties and methods and so it does not always have to redefine them, but anything else that has not been inherited must be deliberately and explicitly defined.
In practical terms, the student should not have to guess as to requirements, instructions, or their status. Abstraction - Abstraction is simplifying complex reality by modeling classes appropriate to the problem, and determining which of the parent class members to inherit to the new child.
Abstraction of the elements of a course seems intuitively simple but can be difficult, even more so for a particular lesson, because it demands that we define many things we typically take for granted, have forgotten, or have simply integrated into 50! The instructor must adopt the outside view, that of the student newly approaching the learning environment. Polymorphism - Polymorphism allows you to treat derived class members just like their parent class's members.
In other words, the same method will be handled differently depending on who is carrying out the action. Both students would make the same request call the method , but it might be handled differently from an administrative perspective.
The point is that simplicity arises when the interface relies on predictable methods and procedures so that whichever student you are dealing with has the same command set. Flexibility arises because even though the same action is requested by different classes of students, the request is handled according to the rules defined for that particular class of student.
The point here is not to 'program' courses and lessons as though they were computer programs, but rather to use these concepts as guides in the deconstruction of learning needs and subsequent reconstruction of more effective and flexible models of instruction.
Furthermore, not every lesson need reflect all of the principles presented in order to be effective. Fusion of Technology and Pedagogical Foundations These principles of deconstruction and reconstruction, when combined with the learning paradigms described by Bloom et al.
To review, Bloom's Taxonomy, or simply 'The Taxonomy', elaborates the cognitive process dimensions of learning in terms of six types, each! Put another way, the instructor can 'wing it' and assume that she is covering the wide range of cognitive skills required by the program of studies. The preferred approach is to incorporate the skills in an array in the lesson classes hence objects themselves, the table indicating which elements have been taken into account in the particular lesson.
In this view, the skills are thus represented as properties of the class available to be referenced externally to other instructors who might want to make use of the lesson object in question.
Further, the object taxonomy properties for an entire course could be queried and assessed in order to determine the nature of the cognitive skills and knowledge inherent in the program of studies. Approaching Instructional Design for DE: To achieve the best results in instructional design for DE, the same guidelines apply, regardless of the nature of the learning task. As a first priority, use well established models of learning to clearly conceptualize specific learning outcomes incorporating the requisite knowledge elements.
The next step is to then follow the principles of relational databases and object-oriented programming to guide the deconstruction of the learning requirements leading to the reconstruction of the instructional model and lessons.
Rolland Eds. Author : John D. The first step is to pick a project of the appropriate sizethis means a project that will take the team no longer than Author : Mohamed E. Transitioning to object - oriented software engineering OOSE is a task with a lot of This book shows how to tailor your own object Object Oriented Technology OOT has many advantages over the traditional software development methodologies.
The availability of consultants makes the Furthermore, they correlated this problem to management's lack of commitment to the human side of IT. Multiple independent objects may be instantiated—or represented—from the same class and interact with each other in complex ways. A simple example would be a class representing a person. A family could be constructed by instantiating person objects from the class for each member of the family.
Each person object would contain different data attributes since each person is unique. By defining sets of classes that represent and encapsulate objects in a program, the classes can be organized into modules, improving the structure and organization of software programs. Thus, developers often use OOP as a tool when they need to create complex programs since they are easier to reason in terms of classes and their relationships.
Object-oriented programming has four basic concepts: encapsulation, abstraction, inheritance, and polymorphism. Even if these concepts seem incredibly complex, understanding the general framework of how they work will help you understand the basics of an OOP computer program. Below, we outline these four basic principles and what they entail:. Just like a pill "encapsulates" or contains the medication inside of its coating, the principle of encapsulation works in a similar way in OOP: by forming a protective barrier around the information contained within a class from the rest of the code.
In OOP, we encapsulate by binding the data and functions which operate on that data into a single unit, the class. By doing so, we can hide private details of a class from the outside world and only expose functionality that is important for interfacing with it.
When a class does not allow calling code access to its private data directly, we say that it is well encapsulated. Example: Elaborating on the person class example from earlier, we might have private data in the class, such as "socialSecurityNumber," that should not be exposed to other objects in the program. If a method is written in the person class to perform, say, a bank transaction called "bankTransaction ," that function could then access the "socialSecurityNumber" variable as necessary.
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