Is Jack Nicholson really crazy? Or angry? Is this method acting, or is he playing his film persona? In the fourth part of a series on film appreciation leading up to the Dubai International Film Festival (DIFF), we look at what makes movie actors tick

There's no job quite like it. Cloaking yourself in another person's identity: his speech, his manner of dressing, his gait, even his bad habits. This is how actors earn a quid.

Sometimes the persona is chilling. Think of Anthony Hopkins and his cool, calculating portrayal of Hannibal Lecter in Silence of the Lambs, or the semi-crazed vigour of Jack Nicholson in One Flew Over the Cuckoo's Nest. Yet there's method in the madness.

Movie actors are the faces of film-making, the pin-up celebs we most associate with the big screen, But what skills to they require? And what methods do they use to deliver a performance that seems real?
This week, Friday discusses acting with Kim Bigelow, assistant professor of mass communication at the American University of Sharjah.

Professor Bigelow has more than 17 years' experience in the TV and film-making industry and has written, produced and directed more than 200 professional films.

What is a good performance? What do we mean when we talk about a brilliant piece of acting?
When I was supervising auditions for a film project, the casting agent would sometimes say, "Well, she - or he - really nailed that one!"

What the agent meant was that the actor had given a reading of the script which had no false notes and clearly defined the character. When asked how they created a role, many actors say they had "felt the moment".

This seems to mean that the actor was so thoroughly immersed in the performance they weren't ?acting' at all.

In one scene with Jack Lemmon in the film Goodbye Mr Roberts, (director) John Ford kept shouting "Less!" after each take. In exasperation, Jack Lemmon asked, "Well, if I do any less, I won't be acting at all," to which Ford replied, "Yes!"

Clearly, John Ford didn't want the actors in his film to act - he wanted them to be real. Lemmon related later this was probably the best advice on acting he ever received.

When discussing acting for film or TV, there are really two issues: subtlety of performance and consistency.

Because the camera is often so close to the actor, every nuance of movement or gesture can be seen by the audience. It also means any loss of concentration, the slightest stepping out of character will be glaringly obvious to the audience.

Consistency of performance means giving the same performance from one take to the next. For the actor, this is really a problem of acting for the film editor.

If an actor gives a very passionate read in the wide shots but gives a very subdued read in the close-ups, the editor will be at a loss as to how to cut the two performances together.

Great actors such as Jack Nicholson, Meryl Streep, Dustin Hoffman and Cate Blanchett, to name a few, give consistently strong performances, even though the individual takes of that performance may be separated by hours or even days.

What is method acting?
Constantin Stanislavsky, considered the father of modern acting, developed the concept of method acting. This approach offers ?methods' by which the actor can enter the emotional core of a character.

In method acting you have such a complete understanding of the emotions felt by the character in the particular situation that when you are performing your role you ?become' the character and are actually feeling the character's emotions and reacting the way the character would react in real life.

What are the benchmarks of an actor's skill?
Are actors supposed to flesh out and inhabit the characters they play to bring them to life? Obviously, the actor must understand the character. However, the benchmark of a great performance is not just knowing the character, but for that character to act like he is experiencing the situation for the first time, just hearing the dialogue of the other actors for the first time.

For this, actors must have the dialogue completely memorised or, alternately, not memorised at all.

One of the key method acting techniques is called ?sense memory'. This requires the actor to relive moments in his life that were similar to the problem or situation facing his character.

By drawing on these moments, the method actor can blend his own life with the character he is playing and create more real moments.

Lawrence Olivier, Ian MacKellan, Emma Thompson and Anthony Hopkins are all classically trained British actors. For these actors a performance is broken into ever smaller parts and analysed for what physical or verbal technique will most successfully communicate the moment.

The best example I have ever heard of the difference between the classic and method approach was when Lawrence Olivier and Dustin Hoffman worked together on Marathon Man. One scene required Hoffman to act as if he had been tortured by Olivier. Hoffman stayed awake for three straight days as a way of creating the reality of the moment.

Olivier observed Hoffman's bedraggled appearance and remarked, "You should really try acting old boy. It's ever so much easier."

Method acting (becomes problematic) when the actor goes dry and cannot connect emotionally, or when the character in a script is poorly drawn and allows only limited emotional engagement.

The classically trained actor can look at a weak character and still break the scene down into specific movement requirements.

How do we know when a performance is good? Is it when you don't see Tom Hanks any more, but you see a scared little kid who turns 30 overnight or a castaway on an island? With the intense visibility of popular culture these says, is this transformation possible? Tom Hanks has a hang-dog wide-eyed look in every role. Is that acting?
Here you are really talking about the difference between the character actor and the actor as ?persona'. One of the problems of being a celebrity star is meeting the expectations of the audience.

This can mean pretending to be different characters, but still making sure the personality the audience has paid to see shines through.

Tom Hanks, for instance, is a fine actor who must sometimes feel caught by his film persona. Hanks has been called the ?everyman' actor. His persona is that of the easygoing, somewhat innocent young man caught up in weighty affairs.

Hanks often accepts roles that challenge this persona, for instance, the hired killer in The Road to Perdition. However, even in this the audience embraces not Tom Hanks as a cold-blooded killer, but as the more familiar persona of kindly family man trying to protect his son.

What makes actors like Jack Nicholson, Al Pacino and Robert De Niro so good?
All great actors have the ability to make good acting decisions. These decisions relate to the four other common denominators: timing, listening and reacting, body control and dedication.

Some of those acting decisions are very calculated and are the result of a careful analysis of the script situation and character (craft approach) while some acting decisions are made instinctively (method approach). But, in any case, these decisions determine howsuccessfully an audience accepts a character as real.

Charlie Chaplin was once at a party where a great Spanish matador was demonstrating the intricate movements of the cape used in the bullfight. Chaplin took the cape and executed the exact same cape movements perfectly.

The matador was amazed since it had taken him years of practice to be able to execute the flowing movement of the cape.

All great actors have exceptional body control. The twitch of a leg, extending a hand or any other body language movement are the tools great actors call on to help them create a unique character.

Finally, great actors all seem to be extraordinarily dedicated. Talking with Paul Newman during a break in the shooting of Road to Perdition, Tom Hanks related how amazed he was Newman was still passionate about improving his acting skills.

Tom Cruise is another example of a completely dedicated actor. It would be easy for Cruise to sit back and depend on his fame and good looks to maintain his career, but instead he takes on difficult roles that require months of preparation.

Cruise's dedication results in exceptional performances in films such as Rain Man, Jerry Maguire and The Last Samurai.

Certain actors always take on certain kinds of roles; why is that? For example, Meg Ryan is always cast in slightly ditzy roles in chirpy romantic comedies.

You do see certain actors playing the same kind of character over and over. Meg Ryan's roles in Sleepless in Seattle, When Harry Met Sally or You've Got Mail certainly seem similar. However, her roles in In the Cut and Proof of Life show a greater range of acting ability.

The question may come down to audience expectations. In Against the Ropes, for instance, Ryan plays a pushy, hard-headed fight manager.

While Ryan's performance is excellent, audiences generally rejected this character portrayal and the film was not as successful as her other films.

It can be difficult for an actor to break out of an established 'type'. Sylvester Stallone and Arnold Schwarzenegger only occasionally break out of their action hero persona and even though they are getting too old to play action heroes, audiences are often very reluctant to embrace other character roles.

This (is) one of the challenges for established film actors. As they grow out of their general type, they may need to reinvent themselves.

Faye Dunaway, Susan Sarandon and Diane Lane all re-established themselves as older character actors when they were unable to play their more traditional roles of ingenue or femme fatale.

How does the relationship between director and actor work? Do actors take well to someone telling them what to do and how to do it?
Actors in films usually do not know what level of emotion is correct for a particular scene as it relates to other unshot scenes. Films are usually shot out of order.

For instance, all of the scenes that take place in one location will be shot at the same time even if those scenes take place at different times in the movie.

The actors need to be guided as to what their character is doing and feeling at the time a particular scene is being shot.

Some directors are notorious for their dictatorial control. Alfred Hitchcock brooked vey little discussion about how a role should be played.

When Paul Newman asked Hitchcock about the motivation of his character in Torn Curtain, Hitchcock is reported to have replied, "Your motivation, Mr Newman, is the $250,000 you are being paid."

Some directors such as Francis Ford Coppola, Martin Scorsese and Roman Polanski, work very closely with their actors.

Coppola fumed in private when Marlon Brando showed up on the set of the over-budget Apocalypse Now without even having looked at the script and then insisted on taking three days to work with Coppola on his character.

Brando's resulting performance was wonderful, but the time Coppola spent with him and other factors contributed to him giving away much of the profit he should have made on the film.

In fairness, the ability of the director to work with actors often depends on time. If a film has a tight shooting schedule, the major concern of the director may be to just get the film shot.

Who decides which actors will appear in a particular film? How does the process work?
The decision on which actor or actress will be hired for a particular film varies with each production.

In most instances, it is the producers who make the casting decisions. Those decisions are often based on budget as much as who is right for a particular role.

In other cases, the director may make the final choice, or even sometimes the actors themselves.

For instance, Eddie Murphy's contract often carries a clause giving him approval for who will co-star in the movie wth him. In big productions, it is common for actors to undergo screen tests.

In Gone With the Wind, virtually every major Hollywood actress was tested for the role of Scarlett O'Hara before British actress Vivien Leigh was finally chosen.

Many actors have been so keen to get a particular role that they go to extraordinary lengths to be considered. Actors have been known to pay for their own screen tests or give impromptu performances in parking lots just to be considered.