Attention Deficit Hyperactivity Disorder (ADHD) is a diagnostic term describing patients showing hyperactivity, impulsive behavior, and problems with paying attention (1). Despite the fact that most children at preschool age may show such behaviors, the difference lies in the intensity of given characteristics. If the presence of a given characteristic in a child causes the child to differ from the other children of the same age to a very pronounced degree, then it can be called a “symptom” (2). Children diagnosed with ADHD show the following symptoms: 1) in the domain of attention problems: inability to concentrate during school lessons or the currently performed task; problems with directing their attention to the correct stimulus (e.g. to the teacher) or with paying continuous attention; making simple mistakes in their schoolwork; problems with following complicated instructions; loss of attention; not completing tasks; problems with organizing their activities; losing stationery which is necessary for their schoolwork, 2) in the domain of hyperactivity: high motor activity even in situations when it is not approved by others; continuous arm or leg movements; fidgeting in class; getting up from their seat without permission; wandering around the classroom; running when walking is expected; climbing furniture; problems with playing peacefully; loud behavior, and 3) in the domain of impulsiveness: bursting to answer a teacher’s question; inability to wait for one’s turn; cutting in on the conversations of their peers as well as adults; frequent change of topics during conversation. Although most children are diagnosed with ADHD at school age, Wolańczyk & Komander (3) claim that the syndromes can be observed already in early childhood. What is more, the symptoms do not fade away as the young person is growing up – on the contrary, they often lead to other psychological and social problems (3).

ADHD treatment methods may be divided into two groups – pharmacological and non-pharmacological (3). A review of treatment studies published by Trout, Lienemann, Reid and Epstein (4) showed that the literature pays too little attention to research which assesses the effectiveness of intervention for children with ADHD without introducing pharmacological means. Hyperactivity treatment without administering medicines ususally focuses on psychoeducation of parents and other people involved in taking care of the child, as well as on applying therapeutic intervention based on the learning theory. The behavioral approach (applied behavior analysis) is recommended due to its effectiveness (5, 6), and also to the fact that the techniques may be used not only by professionals, but also by parents and teachers (7).

One of the basic principles which is a foundation of many behavioral techniques is reinforcement, that is, the process as the result of which the probability of the occurrence of a given behavior increases. Rewarding, especially with praise and appreciation, is very effective in the process of raising typically developing children. In the case of children who do not develop normally, social reinforcement can be aided by additional motivational systems, for instance a token system. Pfiffner (1) states that schoolchildren with ADHD often demand tangible and concrete methods of reinforcing the desirable behavior.

Although the literature reports on the effectiveness of using a token system in a population of children who are not developing normally, very few studies specifically concern ADHD children. They mostly concentrate on modifying behavior in a school environment, even though it is well known that the combination of behavioral therapy conducted in class with training the parents achieves the best results. For instance, Gannon, Harmon and Williams (8) conducted an experiment in which a 12-year-old ADHD boy participated. They introduced a token collecting program at the boy’s home, while the participant was doing his homework. The results showed that the boy’s concentration on the task being currently performed rose significantly in comparison to his attention level before the introduction of the token system.

One important issue for the evaluation of a therapeutic program’s effectiveness is generalization, i.e. the transfer of effects of therapy to other environments and behaviors. Pfiffner (1) claims that ADHD children do not generalize the acquired skills and that they do not transfer them to other settings than the training ones. Research demonstrates that stopping the “token rewards” causes a relapse to the ways of behavior observable before the introduction of intervention (9), unless generalization promoting strategies are applied during therapy from the very beginning. Thus, the occurrence of generalization in ADHD children can be mainly observed in those studies where the procedures are implemented by people in the child’s everyday environment, not only the experimenters (e.g. 10, in 9, 11, 12).

Summing up, the scholarly literature concerning therapeutic interventions for children with ADHD demonstrate the token system’s usefulness in behavior modification. Nevertheless, this intervention ought to be introduced not only at school, but also at the child’s home. Moreover, generalization should be actively promoted. Therefore the aim of the conducted study was to verify the following hypotheses: 1) the introduction of intervention concerning hyperactivity shall decrease the amount of problem behavior related to this symptom and shown at home, 2) the introduction of intervention concerning hyperactivity shall not influence the amount of problem behavior related to the remaining symptoms and shown at home, 3) at home, the introduction of intervention concerning hyperactivity shall not influence the amount of problem behavior related to all symptoms and shown at school.

Three children – boys at the age of eight to nine years – participated in the study. They were second and third grade students at different grammar schools in Warsaw. The children were diagnosed with ADHD and were recruited to the study through recommendation by school psychologists. During the course of the study the children did not take any medicines. Additionally, neither the participants nor their parents attended any therapeutic classes. Every child’s parents expressed their written consent for the child’s participation in the study, after being informed about the study’s procedure. Also the children participating in the study were asked for their consent.

The study took place at the boys’ homes as well as the schools they attended. At the children’s homes, the experimental sessions were conducted in a given boy’s room, which were rather barren and without many distractions. The observations conducted at school took place in the classrooms, during regularly held lessons. The classroom decoration as well as the arrangement of the seated children did not change during the conducted study.

The experimental sessions took place three times a week. Twice a week at the subject’s homes and once a week at their schools. At home the study took place in the afternoon, while at school – in the morning. The experimental sessions at home lasted 90 min (twice 45 minutes with a 10 minute break between the sessions). During the session, the subjects were sitting at their desk, while their task was to do homework set for the following day. If the homework was done before the end of the session, the subjects performed exercises improving their visual-motor coordination. During the break the boys rested or played with toys. At school, there were no experimental sessions, just observational ones. The subjects were supposed to perform tasks related to the teacher’s instructions, just like the rest of the children. During the breaks the subjects passed their time together with their peers.

The behaviors measured during eight weeks of the experiment were three ADHD symptoms: hyperactivity, inattention and impulsiveness. However, the hyperactivity measurement was regarded as the main measurement (MM), while the measurements of inattention and impulsiveness – as supplementary (SM).

Hyperactivity was described as excessive activity. Its symptoms were: 1) nervous movements of arms, legs and feet, or fidgeting on the chair; 2) leaving the seat when remaining seated is required; 3) excessive restlessness or performing actions which do not comply with the standards prevailing in the environment; 4) noisiness at play or problemies with remaining peaceful at rest.

Inattention was defined as engaging in one or more of the following behaviors: 1) making frequent mistakes in schoolwork or other activities; 2) repeated failure to concentrate on the tasks or activities connected with play; 3) lack of reaction to what the child is being told; 4) repeated failure to follow the instructions or complete schoolwork or homework; 5) losing or forgetting items which are necessary for performing the tasks; 6) easy reversibility of attention by external stimuli; 7) forgetfulness during the everyday activity.

Impulsiveness was defined as engaging in one or more of the following behaviors: 1) answering a question before it has been formulated; 2) problems with waiting for one’s turn at games and other group situations; 3) interrupting or disturbing others; 4) excessive talking irrespective of social constraints.

To conduct the measurements, the partial interval measurement was employed. The intervention was based on, first, the introduction of the four rules of “good behavior”. Their wording was: 1) We sit straight in the chair, 2) During the lesson we sit at the desk, 3) We walk, not run, 4) We behave quietly during classes or at play. Moreover, a token economy was introduced. While being observed, the subject received a token after every 5 minutes of session. The child obtained a token only if during an interval no problem behavior occurred. The awarding of tokens was also accompanied by feedback for the participant: “You behave according to our rules, well done! You get a token” or “You don’t follow our rules, you don’t get a token”. After obtaining a certain number of tokens the subject could exchange them for their prize of choice. For obtaining at least 7 tokens during a 90-minute class the subject received a “daily” award. This consisted of social activities (e.g., playing a game). After completing the second session of the week, the subject also summed up his tokens. This time, apart from the “daily” prize, he also received a “weekly” prize – a chocolate bar and chewing gum, on condition that during the two experimental sessions (three hours – breaks excluded) the participant collected at least 14 tokens.

The study – but only for the sessions conducted at home – made use of the single-subject experimental design with a return to baseline (the reversal ABAB design). The study began with measuring the baseline before introducing intervention (the “A” phase), next intervention was introduced (the “B” phase or “intervention”), and then both phases were repeated. At school, on the other hand, the measurement was conducted only in the first phase – A, the second phase of the experiment was not administered. The goal was to check if the intervention applied at home would be generalized to the school environment. In all, the experiment consisted of four phases. The first was an initial baseline measurement – the A1 phase, next the intervention – the B1 phase, then a return to the baseline measurement – the A2 phase, and the introduction of intervention yet again – the B2 phase. Each phase lasted two weeks.