• WordNet 3.6
    • adj challenging requiring full use of your abilities or resources "ambitious schedule","performed the most challenging task without a mistake"
    • adj challenging disturbingly provocative "an intriguing smile"
    • adj challenging stimulating interest or thought "a challenging hypothesis","a thought-provoking book"
    • ***


  • Yoshihisa Tabuchi
    Yoshihisa Tabuchi
    “It's always the challenge of the future, this feeling of excitement, that drives me.”
  • Travis White
    Travis White
    “Dreams can often become challenging, but challenges are what we live for.”
  • Source Unknown
    Source Unknown
    “You can't expect to meet the challenges of today with yesterday's tools and expect to be in business tomorrow.”
  • Lou Holtz
    “How you respond to the challenge in the second half will determine what you become after the game, whether you are a winner or a loser.”
  • Muhammad Ali
    “It's lack of faith that makes people afraid of meeting challenges, and I believe in myself.”
  • Henry Wadsworth Longfellow
    “Critics are sentinels in the grand army of letters, stationed at the corners of newspapers and reviews, to challenge every new author.”


In literature:

Thus did Captain Pond accept our challenge.
"The Mayor of Troy" by Sir Arthur Thomas Quiller-Couch
So I hurried Daggett up; made him keep on sending challenge after challenge.
"Chapters from My Autobiography" by Mark Twain
Flood and Mr. Fair had arranged for a ride in the flume, and I was challenged to go with them.
"Hidden Treasures" by Harry A. Lewis
She turned to me again, holding out her hand as though she challenged me to refuse it.
"Simon Dale" by Anthony Hope
She held her head a bit high, as if in challenge.
"The Triflers" by Frederick Orin Bartlett
Ojeda finally challenged Nicuesa to a duel which should determine the whole affair.
"South American Fights and Fighters" by Cyrus Townsend Brady
For all that, I must clear the bar, if I was to make good my challenge; and I drew a long breath as I stood a moment and glanced round.
"Sir Ludar" by Talbot Baines Reed
His supremacy as a printer could not be challenged in Bursley.
"Clayhanger" by Arnold Bennett
Still, he could not be angry when, on being challenged, the girl laughed at him.
"The Magnificent Montez" by Horace Wyndham
We would be challenged, then brought down.
"Tarrano the Conqueror" by Raymond King Cummings
As she reached for matches the sound of voices beyond the door arrested her, and the challenge of her own name held her attention.
"The Tyranny of Weakness" by Charles Neville Buck
They also repeat to her the song of the Pierides, who challenged them to sing.
"The Metamorphoses of Ovid" by Publius Ovidius Naso
She stood for a second looking at Tenney, the distended beauty of her eyes like a question, a challenge.
"Old Crow" by Alice Brown
Then boldly his eyes challenged both men.
"Trusia" by Davis Brinton
You will be challenged, and you will give the word, 'For Freedom,' and the sign I showed you.
"The Red Symbol" by John Ironside
He felt that a challenge had been passed and accepted.
"The Guarded Heights" by Wadsworth Camp
In this pocketed bit of wilderness, the incline had been built years ago, and it had been a challenge to Nature's mandate of isolation.
"The Tempering" by Charles Neville Buck
She was a little surprised at its poignant, almost challenging note.
"The Hillman" by E. Phillips Oppenheim
The first challenge which the young American received in London was from Herr Loewenthal.
"The Exploits and Triumphs, in Europe, of Paul Morphy, the Chess Champion" by Frederick Milnes Edge
Surely he'd not challenge the Moghul.
"The Moghul" by Thomas Hoover

In poetry:

O the bliss upon the plains,
Where the joining heroes clashed
Shield and spear, and, unabashed,
Challenged with hot chariot-reins
Gods!—they glimmer ocean-washed.
"Cassandra" by George Meredith
'Farewell timeless expanse of passing years!
Farewell, woman who flung your challenge steeled
Against the abyss of humiliations:
For it is I who am your battlefield!
"August" by Boris Pasternak
No sound of tramping hoofs, no yelling pack,
No merry winding of the hunter's horn,
Rous'd sleeping echo to fling boldly back
The challenge rude, as if in mocking scorn.
"Elegy" by Janet Hamilton
The sounds that met my boyish ear
My inward sense salute,--
The woodnotes wild I loved to hear,--
The robin's challenge, sharp and clear,--
The breath of evening's flute.
"Our Home—Our Country" by Oliver Wendell Holmes
The yellow kitten purred on the hearth,
While the kitchen clock, with its frame of oak,
In the corner stood, like a sentinel,
And challenged time with its measured stroke.
"Phoebe's Wooing" by Horatio Alger Jr
One moment, as if challenging the storm,
Chocorua's tall, defiant sentinel
Looked from his watch-tower; then the shadow fell,
And the wild rain-drift blotted out his form.
"Storm On Lake Asquam" by John Greenleaf Whittier

In news:

Keeping them is the challenge.
In sharp turnaround, nation challenges Saudi Arabian production.
The Aragon weekend was particularly challenging for the Ducati Team and its riders, who are working to speed up the development of the Desmosedici.
TOLEDO, Ohio – The pursuit of the Hoosier Tire Superspeedway Challenge Award will feature eight races in 2013, up from seven in 2012, following yesterday's announcement of an ARCA Racing Series event at Kentucky Speedway.
The Nixon Surf Challenge heads to the Lofoten Islands in Norway.
To actually start drilling, Shell needs federal certification of the Arctic Challenger, shown above.
Eli is facing arguably the most challenging year of his career, yet he remains confident.
On Your Marks is a monthly column where reporter John Marks takes on competition from the greater Lake Wylie and Fort Mill areas, challenging them in their field of expertise and profiling what makes them special.
Strikeforce women's bantamweight championship Ronda Rousey applies an arm bar to challenger Sarah Kaufman during their bout Saturday at Valley View Casino Center.
China's newest stealth fighter prototype is made in the People's Republic and could pose a challenge to US air power.
CHINA is challenging India as a low-cost home for software development.
Arnold Palmer 's younger grandson gets call for Father/Son Challenge.
During the fourth week of their million dollar challenge the community puts on a high-end wine and dine event, but with expensive ticket prices and an inexperienced staff, will anyone show up and will they be satisfied with the event.
Okay, I know this doesn't look for reals, but Lord Monckton, a former policy adviser to Margaret Thatcher, has challenged Al Gore to a Climate Change Challenge (for the fancy cursive you'll have to click on the link).
Navigating today's roads can be challenging for all drivers, but military veterans face particular challenges behind the wheel.

In science:

While in the initial stages of a system, this challenge has been echoed as the ‘cold-start’ problem (also referred to as the ‘day-one’ or ‘early-rater’ problem), it is also ubiquitous during the lifetime of a system.
A Connection-Centric Survey of Recommender Systems Research
The lack of standards to represent such information and its sources (e.g., logs) in a uniform manner make interoperability among recommender systems a challenge [19, 30].
A Connection-Centric Survey of Recommender Systems Research
Furthermore, connecting users wi th similar interests who have rated different items (e.g., ‘we both read world politics online, but he ranked webpages, while I ranked pages’) is challenging.
A Connection-Centric Survey of Recommender Systems Research
The need for an optimized model is motivated by the ma jor challenges faced in a basic OAI-PMH model, which can be seen in Figure 1.
A Scalable Architecture for Harvest-Based Digital Libraries - The ODU/Southampton Experiments
However, the proof of such a statement does present some challenges.
A law of large numbers for random walks in random mixing environments
The challenge in the case of quantum integer spin chains is particularly exciting as it deals with the question of the fate of the Haldane phase in the presence of disorder.
Phase diagram of the random Heisenberg antiferromagnetic spin-1 chain
Computational studies of lattice dynamics and structural stability in strongly correlated electronic systems is a challenging theoretical problem.
Linear Response Calculations of Lattice Dynamics in Strongly Correlated Systems
There are many other challenging problems for which the general framework outlined here can be useful.
Linear Response Calculations of Lattice Dynamics in Strongly Correlated Systems
We consider this issue as one of the most challenging problems for future investigations.
Random Matrices close to Hermitian or unitary: overview of methods and results
At the present time, doing so appears to present a severe challenge to the available technologies.
Spectral statistics of the k-body random-interaction model
VHV, 20 KV level) to each of three electrodes, which will be challenging to distribute over a large area array.
Development of a Hybrid Photo-Diode and its Front-End Electronics for the BTEV Experiment
Since they are non-extensive and non-additive, the construction of an appropriate thermodynamics is a challenging problem.
Generalized thermodynamics and Fokker-Planck equations. Applications to stellar dynamics, two-dimensional turbulence and Jupiter's great red spot
Going to light quark masses in unquenched QCD simulations is a great challenge for computations because known algorithms have a substantial slowing down towards small quark masses.
On the price of light quarks
While the ‘2D Conjecture’ has been challenged and shown to be likely incorrect for electronic systems (Reviewed in ), here I will focus on classical waves.
Are waves all localized in two dimensional random media?
Understanding drag reduction then becomes a usual challenge of theoretical physics.
A simple model for drag reduction