Introduction

As toddlers emerge from infancy, dramatic changes are taking place in their physical development. By the start of their second year, infants transition from moving around on all fours as crawlers, to taking their first upright walking steps (Adolph & Berger 2006). As far as mobility is concerned, they are relatively independent of their parents. A glance around any supermarket will usually identify some harried parent trying to control a toddler while attempting frantically to fill their basket or trolley with groceries.

Toddlers have discovered the advantages of standing and walking. To their parents’ concern they are now able to reach the top of kitchen benches, tables and door knobs, opening up whole new worlds for exploration. Standing on tip-toe they can reach for knives or saucepans. Although a little unsteady on their feet at first, toddlers revel in their newfound mobility, charging from room to room in the house, squealing with delight. Stairs are a fatal attraction and the despair of parents. In parks, the raised cement edges of flower beds are another challenge for the child’s developing physical skills. Bruises on the shins and lower legs are the red badge of courage for the toddler striving to refine walking and running skills.

Introduction

As for the second edition, the third edition of Child, Adolescent and Family Development is written for all those who entertain an interest in children’s and adolescents’ lives, and for all those who appreciate the curiosity, strength and resilience of growing children and young people. It is a book about the richness and diversity of children’s and adolescents’ lives, considered in the context of the family. In turn, the family and its individual members are viewed in the broader historical context of society and culture. This book is also about change. All that it discusses is considered to be in a process of flux and change.

In planning and writing the third edition we have taken note of the feedback received from tertiary teachers and their students regarding the content of the book. A number of features in the second edition were consistently endorsed by readers including the ‘broad sweep’ of the book as it placed human development in an historical, philosophical and cultural context. Readers also commented favourably on the Australasian flavour which considered child development in an international context. Finally, appreciation was expressed for the ‘readability’ of the text.

1. ‘Things that make children sweet-tempered’

2. ‘When I’m a Duchess,’ she said to herself (not in a very hopeful tone though), ‘I won’t have any pepper in my kitchen at all. Soup does very well without – Maybe it’s always pepper that makes people hot-tempered,’ she went on, very pleased at having found out a new kind of rule, ‘and vinegar that makes them sour – and barley-sugar and such things that make children sweet-tempered. I only wish people knew that: then they wouldn’t be so stingy about it, you know.’

3. Lewis Carroll, Through the Looking Glass

Introduction

The world of the primary school child is to a large extent a world closed to adults inasmuch as it is a society of its own. There is a timeless quality associated with this period of children’s lives. Primary school children move into their own world of magic, fairytale and ritual, which by its very secrecy excludes adults. In her book To Kill a Mockingbird (1960) Harper Lee allows us an all too rare glimpse into the secret world of children, a world characterised by secrets, rituals and rules. More recently, the success of the ‘Harry Potter’ series of books captures signifi cant themes that entrance primary school children: ‘HARRY POTTER is a wizard! Along with Ron and Hermione, his best friends, Harry is in his third year at Hogwarts School of Witchcraft and Wizardry’. A further glimpse into the world of middle childhood is provided by Bart Simpson’s Guide to Life (Groening 1993). This book offers all sorts of ‘advice’ about parents, school and peers for primary school children.

Introduction

Accompanying the toddler’s considerable advances in physical development are advances in the way the child thinks (advances that would go some way towards eventually helping Alice answer the questions put to her by the White Queen and the Red Queen!). In this chapter consideration is given to the toddler’s increasingly sophisticated ways of thinking about the world. The concept of intelligence is discussed and various theoretical approaches to the study of cognition are outlined. As we have seen in Chapters 3 and 7, a significant contributor to our knowledge in this field is Jean Piaget; although his first research was published between 1924 and 1932, his work was not recognised in Australia until the 1960s. Similarly, the Russian psychologist Lev Vygotsky was researching and writing about children’s thinking over approximately the same period; his ideas also are now well accepted in countries such as Australia. The signifi cant matter of language development is also considered in this chapter. The family life-cycle: 10 considers the role of the mother after the birth of the first child.

Computer architecture is a fast evolving field, mostly because it is driven by rapidly changing technologies. We have all been accustomed to phenomenal improvements in the speed and reliability of computing systems since the mid 1990s, mostly due to technology improvements, faster clock rates, and deeper pipelines. These improvements have had a deep impact on society by bringing high-performance computing to the masses, by enabling the internet revolution and by fostering huge productivity gains in all human activities. We are in the midst of an information revolution of the same caliber as the industrial revolution of the eighteenth century, and few would deny that this revolution has been fueled by advances in technology and microprocessor architecture.

Unfortunately, these rapid improvements in computing systems may not be sustainable in future. Pipeline depths have reached their useful limit, and frequency cannot be cranked up for ever because of power constraints. As technology evolves and on-chip feature sizes shrink, reliability, complexity, and power/energy issues have become prime considerations in computer design, besides traditional measures such as cost, area, and performance. These trends have ushered a renaissance of parallel processing and parallel architectures, because they offer a clear path – some would say the only path – to solving all current and foreseeable problems in architecture. A widespread belief today is that, unless we can unleash and harness the power of parallel processing, the computing landscape will be very different very soon, and this dramatic change will have profound societal impacts.

Aimee (now aged 24 years)

The sentiments expressed by the fictional teenager Adrian Mole capture some of the complexity surrounding the physical changes that occur during this period of life. The term ‘adolescence’ is derived from the Latin adolescere, which means ‘to grow up’ or ‘to grow to maturity’. Adults’ feelings about adolescents are often pessimistic or somewhat ambivalent. The 8th-century BC Greek poet Hesiod’s opinion of the youth of his time would not be out of place in some quarters today:

Introduction

Children’s understanding of the world and their place in it undergoes rapid development during the pre-school years. This understanding is accompanied by significant changes in their use of language. The pre-schooler’s behaviour is dramatically different from that of a child during the ‘terrible twos’ (just ask any parent!). The temper tantrums, refusals to comply and use of the word ‘No!’ so characteristic of the 2-year-old contrast sharply with the 4- to 5-year-old’s ability to comprehend instructions, comply with requests and generally reason about the world.

This chapter focuses on the nature of children’s cognitive development in the pre-school period. Consideration is given to the theories of Piaget, Bruner and Vygotsky on the way children’s thinking develops during this period. An examination is also made of children’s language development in the pre-school years.

1. ‘Two of the fairest stars’

2. Two of the fairest stars in all the heaven,

3. Having some business, do entreat her eyes

4. To twinkle in their spheres till they return.

5. The brightness of her cheek would shame those stars,

6. As daylight doth a lamp, her eyes in heaven

7. Would through the airy region stream so bright,

8. That birds would sing, and think it were not night.

9. See how she leans her cheek upon her hand.

10. O that I were a glove upon that hand,

11. That I might touch that cheek.

12. William Shakespeare, Romeo and Juliet, Act 2, Scene 2 Lines 15–23

Introduction

Research into this period of the life-cycle continues to gather pace (e.g. Howard et al. 2010). As we have seen in Chapter 18 , the physical changes occurring early in this single phase of the life-cycle are quite dramatic, characterised by a sudden growth spurt, pimples, appearance of body hair and development of the reproductive organs. At the same time adolescents acquire a greater capacity for rational and abstract thought associated with risk-taking, limit testing and experimentation. For some individuals, youth, particularly early youth, represents a time of increased self-consciousness and egocentrism. Adolescents face major developmental landmarks, including achieving independence from parents, acquiring the rights to leave home and school, vote, have sex, drink alcohol and drive a car. At this time, many young people make significant decisions about their future careers. In contemporary Western countries such as Australia adolescents must also come to grips with other important issues that have implications for their future life. These include the uncertainty of employment opportunities and the extended time that must often be spent at school as a result, health issues, and broader questions regarding the future such as conservation of the environment and global warming.

1. Alone

2. From childhood’s hour I have not been

3. As others were – I have not seen

4. As others saw – I could not bring

5. My passions from a common spring –

6. From the same source I have not taken

7. My sorrow I could not waken

8. My heart to joy at the same tone –

9. And all I loved – I loved alone …

10. Edgar A. Poe (1829)

Introduction

The nature of adolescent thinking has been the subject of a good deal of research. During adolescence individuals acquire a greater fl exibility in the way they think and their cognitive abilities come to more closely resemble those of an adult. Significant advances have been made in relation to our understanding of the neurology underpinning adolescent brain development. Adolescents are able to think in abstract terms and consider at length the nature of complex concepts such as beauty, truth and justice. This skill is promoted by their ability to entertain different ideas at the same time and to hypothesise about possibilities. In adolescence, individuals develop further their ability to put themselves in the place of another and then to consider such questions as: ‘What would it be like to be a person from a different cultural background?’

Introduction

This chapter will consider a number of the major theories listed in Figure 1.1 (see Chapter 1), including psychoanalytic, psychosocial, behavioural, humanistic, cognitive-developmental, social systems and socio-cultural theories. In this third edition additional information is provided regarding evolutionary, ecological and dynamic systems theories. In discussing the various theories, the work of key writers and researchers will be examined, namely Sigmund Freud, Erik Erikson, Ivan Pavlov, Burrhus Skinner, John Watson, Albert Bandura, Abraham Maslow, Jean Piaget and Gregory Bateson. The third in the Family Life-cycle series introduces the concept of family.

Theoretical development

As defined by the Macquarie Dictionary, a fact is ‘what has really happened or is the case; truth; reality; something known to have happened’. Research into child development is uncovering facts at a rate that sometimes outstrips our ability to integrate them into a coherent framework. Facts are very important to any science.

CHAPTER OVERVIEW

Modern computer systems are becoming increasingly complex as more devices and functionalities are integrated. Throughout the entire design cycle of systems, simulation is a crucial tool for computer architecture researchers to evaluate novel ideas and explore the design space. Compared with hardware prototyping and analytic modeling, simulation strikes a better balance between accuracy, cost, flexibility, and complexity. As the design complexity of state-of-theart microprocessors keeps growing and manufacturing costs skyrocket, computer architecture simulation has become critical.

Simulations are pervasive in computer architecture research and design and affect the productivity of these activities to a great extent. Productivity is impacted at two levels: (1) the time and effort spent on developing the simulator and (2) the time consumed on running simulations with representative benchmarks. The dramatic growth of the integration density of microprocessor chips provides computer architects abundant on-chip real estate to enhance computing power with more complex architectural designs. In addition, power and reliability have turned into critical design constraints. Building a simulation infrastructure that allows a designer to consider performance, power, and reliability in a single unified framework leads to significant cost and delays in simulator development. Another direct consequence of a complex infrastructure is that simulation itself slows down, increasing the turnaround time for each design state exploration. Simulation slowdown is becoming particularly acute as computer architecture moves into the chip multiprocessor (CMP) era. The current approach of simulating CMPs with growing numbers of cores in a single thread is not scalable and cannot be sustained over time.

CHAPTER OVERVIEW

The processor and its instruction set are the fundamental components of any architecture because they drive its functionality. In some sense the processor is the “brain” of a computer system, and therefore understanding how processors work is essential to understanding the workings of a multiprocessor.

This chapter first covers instruction sets, including exceptions. Exceptions, which can be seen as a software extension to the processor instruction set, are an integral component of the instruction set architecture definition and must be adhered to. They impose constraints on processor architecture. Without the need to support exceptions, processors and multiprocessors could be much more efficient but would forgo the flexibility and convenience provided by software extensions to the instruction set in various contexts. A basic instruction set is used throughout the book. This instruction set is broadly inspired by the MIPS instruction set, a rather simple instruction set. We adopt the MIPS instruction set because the fundamental concepts of processor organizations are easier to explain and grasp with simple instruction sets. However, we also explain extensions required for more complex instruction sets, such as the Intel x86, as need arises.

Since this book is about parallel architectures, we do not expose architectures that execute instructions one at a time. Thus the starting point is the 5-stage pipeline, which concurrently processes up to five instructions in every clock cycle. The 5-stage pipeline is a static pipeline in the sense that the order of instruction execution (or the schedule of instruction execution) is dictated by the compiler, an order commonly referred to as the program, thread, or process order, and the hardware makes no attempt to re-order the execution of instructions dynamically.

CHAPTER OVERVIEW

Technology has always played the most important role in the evolution of computer architecture over time and will continue to do so for the foreseeable future. Technological evolution has fostered rapid innovations in chip architecture. We give three examples motivated by performance, power, and reliability. In the past, architectural designs were dictated by performance/cost tradeoffs. Several well-known architectural discoveries resulted from the uneven progress of different technological parameters. For instance, caches were invented during the era when processor speed grew much faster than main memory speed. Recently, power has become a primary design constraint. Since the invention of the microprocessor, the amount of chip realestate has soared relentlessly, enabling an exponential rise of clock frequencies and ever more complex hardware designs. However, as the supply voltage approached its lower limit and power consumption became a primary concern, chip architecture shifted from high-frequency uniprocessor designs to chip multiprocessor architectures in order to contain power growth. This shift from uniprocessor to multiprocessor microarchitectures is a disrupting event caused by the evolution of technology. Finally, for decades processor reliability was a concern primarily for high-end server systems. As transistor feature sizes have shrunk over time they have become more susceptible to transient faults. Hence radiation-hardened architectures have been developed to protect computer systems from single-event upsets causing soft errors.

These examples of the impact of technology on computer design demonstrate that it is critical for a reader of this book to understand the basic technological parameters and features, and their scaling with each process generation.

CHAPTER OVERVIEW

Interconnection networks are an important component of every computer system. Central to the design of a high-performance parallel computer is the elimination of serializing bottlenecks that can cripple the exploitation of parallelism at any level. Instruction-level and thread-level parallelisms across processor cores demand a memory system that can feed the processor with instructions and data at high speed through deep cache memory hierarchies. However, even with a modest miss rate of one percent and with 100 cycle miss penalty, half of the execution time can be spent bringing instructions and data from memory to processors. It is imperative to keep the latency to move instructions and data between main memory and the cache hierarchy short.

It is also important that memory bandwidth be sufficient. If the memory bandwidth is not sufficient, contention among memory requests elongates the memory-access latency, which, in turn, may affect instruction execution time and throughput. For example, consider a nonblocking cache that has N outstanding misses. If the bus connecting the cache to memory can only transfer one block every T cycles, it takes N × T cycles to service the N misses as opposed to T cycles if the bus can transfer N blocks in parallel.

The role of interconnection networks is to transfer information between computer components in general, and between memory and processors in particular. This is important for all parallel computers, whether they are on a single processor chip – a chip multiprocessor or multi-core – or built from multiple processor chips connected to form a large-scale parallel computer.