According to Y

According to Y. Mehdipour and D. Balaramulu et al. 2013, “Teacher-student relationships are essential for the achievement of both teachers and students. As part of classroom management, such relationships are the most significant factor in determining teacher and students’ work as successful. The influence of teacher’s behavior plays an important role in the academic achievement of students. As such, a teacher has to display exceptional behavior as a person. Teachers also need to be thoughtful in the way in which they react to students’ comments. Generally, teachers react by using praise, acceptance, remediation, or criticism in responding to students. This encouragement is called reinforcement and is defined as effect on the behavior. (Derk, 1974, as cited in Y. Mehdipour and D. Balaramulu, 2013).
Schunk, (2000) stated that students typically find reinforcing such as teacher praise, free time, privileges, stickers, and high grades. Still, knowing for certain whether a consequence is reinforcing is impossible until it is presented after a response and we see whether behavior subsequently changes (p. 51).

Reinforcement: Positive and Negative Reinforcement:
Milam and Birch (1998), defined reinforcement as the process whereby a reinforcer increases the likelihood of a response (p. 128). N. N. S. Mandah and O. L. Gbarato et al. (2016) stated that, reinforcement is a skill applied to modify or change pupils’ behavior positively not negatively which can be applied by the teacher increase positive behavior of the learners and also discourage learners’ negative behavior. Generally, reinforcement involves those techniques that results in positive alterations of learning behavior. There are two main types of reinforcement- positive and negative reinforcement.
Positive reinforcement is the process in which the teacher encourages positive behaviors of learners to enable them achieve the specific objective(s) of the lesson. The teacher can smile, praise the learner, or make complementary comments such as well done, good, splendid, etc. This process encourages pupils’ attention, maintains motivation and modifies disruptive behavior thereby helping to improve learning (N. N. S. Mandah and O. L. Gbarato et al. 2016).
Negative reinforcement refers to the application of skills and techniques that will reduce, decrease or discourage negative behaviors in the learner. This can be achieved through the teacher giving punishment to the learners as a means of making them improve on their performance or discouraging those behaviors that may have led to the poor performance, shouting at the learner, making such comments as too bad, no, very poor, shaking the head or closing his eyes, etc.
In general, reinforcement has several components as stated by in which seven components of reinforcement were identified and described, and comprise of:

? Verbal reinforcement
? Gestural reinforcement
? Proximity reinforcement
? Contact reinforcement
? Activity reinforcement
? Token reinforcement

However, Mandah et al. 2016 outlined some of the factors that may hinder the proper application of reinforcement by school teachers have been identified by as:
? No students show interest in the application of the skill always
? Insincerity on the part of the teacher in terms of praise.
? Over use of one type of reinforcement and its relativity to others.
Measures to mitigate these factors include frequent application of reinforcement in the classroom and the fact that the reinforcement should be task-centered and not ego-centered.
Reinforcement and Motivation:
According to Dale. H. Schunk (2000) behavior theories define motivation as an increased rate or probability of occurrence of behavior, which results from repeating behaviors in response to stimuli or as a consequence of reinforcement (p. 13). Schunk (2000) further argued that, Skinner’s (1968) Operant conditioning contains no new principles to account for motivation. Motivated behavior is increased or continued responding produced by effective reinforcement. Students motivated to learn choose a task, persist at it, and expend effort to succeed, all of which are behaviors. Internal processes such as needs, cognitions, and emotions are not necessary to explain motivated behavior. Students display motivated behavior because they were previously reinforced for it and because effective reinforcers are present. Consequently, behavioral theories do not distinguish motivation from learning but somewhat use the same principles to explain behavior. (p. 13)

Motivation can be classified into intrinsic motivation and extrinsic motivation, intrinsic motivation is the pleasure and interest in activities that exists within an individual rather than outside pressure. It is the foundation of having enjoyment in performing activity without any external incentives.

Woolfolk (2010) argued that the study of motivation focuses on how and why people initiate actions directed towards specific goals, how long it takes them to get started in the activity. Furthermore, it also directs them on how intensively they are involved in the activity, how persistent they are in their attempts to reach this goals, and what they are thinking and feeling along the way. (p. 376; 411)
According to Stipek (1996), early approaches to the study of motivation were rooted in the literature on extrinsic reinforcement. Within this literature, all behavior, including achievement, was believed to be governed by reinforcement contingencies. Proponents of this approach included B.F. Skinner, who identified different types of reinforcers. Positive reinforcers, or rewards, are consequences that increase the probability of a given behavior they were made contingent on, whereas negative reinforcers are consequences that increase the probability of a given behavior by removing or reducing some negative external stimulus. Punishment, on the other hand, refers to unpleasant consequences that decrease the probability of a given behavior. Under this framework, the teacher’s job is clear: to use good grades and praise to reward desired behavior and bad grades or loss of privileges as punishment. As Stipek notes, this approach is limited to the extent that rewards and punishments are not equally effective for all students, and desired behaviors (such as paying attention) are difficult to reinforce. Moreover, the benefits of extrinsic rewards tend to decay over time (Stipek, 1996).
Because operant conditioning happens so widely, its effects on motivation are a bit more complex than the effects of respondent conditioning. As in respondent conditioning, operant conditioning can encourage intrinsic motivation to the extent that the reinforcement for an activity can sometimes be the activity itself. When a student reads a book for the sheer enjoyment of reading, for example, he is reinforced by the reading itself; then we often say that his reading is “intrinsically motivated”. More often, however, operant conditioning stimulates both intrinsic and extrinsic motivation at the same time. The combining of both is noticeable in the examples that I listed above. In each example, it is reasonable to assume that the student felt intrinsically motivated to some partial extent, even when reward came from outside the student as well. This was because part of what reinforced their behavior was the behavior itself—whether it was making faces, running a mile, or contributing to a discussion. At the same time, though, note that each student probably was also extrinsically motivated, meaning that another part of the reinforcement came from consequences or experiences not inherently part of the activity or behavior itself. The boy who made a face was reinforced not only by the pleasure of making a face, for example, but also by the giggles of classmates. The track student was reinforced not only by the pleasure of running itself, but also by knowledge of his improved times and speeds. Even the usually restless child sitting still for five minutes may have been reinforced partly by this brief experience of unusually focused activity, even if he was also reinforced by the teacher aide’s compliment. Note that the extrinsic part of the reinforcement may sometimes be more easily observed or noticed than the intrinsic part, which by definition may sometimes only be experienced within the individual and not also displayed outwardly. This latter fact may contribute to an impression that sometimes occurs, that operant conditioning is really just “bribery in disguise”, that only the external reinforcements operate on students’ behavior. It is true that external reinforcement may sometimes alter the nature or strength of internal (or intrinsic) reinforcement, but this is not the same as saying that it destroys or replaces intrinsic reinforcement.
Finally, the process application of reinforcement by teachers encourages pupils’ attention, maintains motivation and modifies disruptive behavior thereby helping to improve learning. Reinforcements should be applied in a proper way at rightful time to reap positive outcomes of desired behavior. However, if misapplied it can lead to negative outcomes with poor academic performance/achievements. Academic achievement was enhanced the most by use of three socializing agents (peers, teachers and parents) to reinforce academic behavior. Reinforcement using all three agents was the most effective way to improve achievement (Gauthier et al., 1984, as cited in Y. Mehdipour and D. Balaramulu, 2013).
Motivation plays an important role in students’ learning. There are various techniques of motivation, but use of motivational expressions as positive reinforcement is very helpful in students learning and academic achievement. It enhances the learning and also helps to bring positive changes in the student’s behavior. On the other hand negative reinforcement discourages the students. Teachers with higher qualification and professional degree use more motivational expressions to motivate their students.